 Orders of magnitude (numbers)

This list contains selected positive numbers in increasing order, including counts of things, dimensionless quantity and probabilities. Each number is given a name in the short scale, which is used in English speaking countries, as well as a name in the long scale, which is used in some of the countries that do not have English as their national language.
Smaller than 10^{−100} (one googolth)
 Mathematics — Writing: Approximately 10^{−183,800} is a rough first estimate of the probability that a monkey, placed in front of a typewriter and given adequate food, breaks, and sleep while doing so, will type all the letters of Hamlet on the first try.^{[1]} However, taking punctuation, capitalization, and spacing into account, the actual probability of the monkey typing Hamlet is less: around 10^{−360,783}.^{[2]}
 Computing: The number 5×10^{−324} is approximately equal to the smallest positive nonzero value that can be represented by a doubleprecision IEEE floatingpoint value.
10^{−100} to 10^{−30}
 Computing: The number 1.4×10^{−45} is approximately equal to the smallest positive nonzero value that can be represented by a singleprecision IEEE floatingpoint value.
10^{−30}
(0.000000000000000000000000000001; 1000^{−10}; short scale: one nonillionth; long scale: one quintillionth)
 Mathematics: The probability in a game of bridge of all four players getting a complete suit is approximately 4.47×10^{−28}.^{[3]}
10^{−27}
(0.000000000000000000000000001; 1000^{−9}; short scale: one octillionth; long scale: one quadrilliardth)
10^{−24}
(0.000000000000000000000001; 1000^{−8}; short scale: one septillionth; long scale: one quadrillionth)
ISO: yocto (y)
10^{−21}
(0.000000000000000000001; 1000^{−7}; short scale: one sextillionth; long scale: one trilliardth)
ISO: zepto (z)
 Mathematics: The probability of matching 20 numbers for 20 in a game of Keno is approximately 2.83 × 10^{−19}.
10^{−18}
(0.000000000000000001; 1000^{−6}; short scale: one quintillionth; long scale: one trillionth)
ISO: atto (a)
 Mathematics: The probability of rolling snake eyes 10 times in a row on a pair of fair dice is about 2.74×10^{−16}
10^{−15}
(0.000000000000001; 1000^{−5}; short scale: one quadrillionth; long scale: one billiardth)
ISO: femto (f)
10^{−12}
(0.000000000001; 1000^{−4}; short scale: one trillionth; long scale: one billionth)
ISO: pico (p)
 Mathematics: The probability in a game of bridge of one player getting a complete suit is approximately 2.52×10^{−11} (0.00000000252%)
 BioMed: Human visual sensitivity to 1000 nm light is approximately 1.0×10^{−10} of its peak sensitivity at 555 nm.^{[4]}
10^{−9}
(0.000000001; 1000^{−3}; short scale: one billionth; long scale: one milliardth)
ISO: nano (n)
 Mathematics — Lottery: The odds of winning the Grand Prize (matching all 6 numbers) in the US Powerball lottery, with a single ticket, under the rules as of August 2009^{[update]}, are 195,249,053 to 1 against, for a probability of 5.12×10^{−9} (0.000000512%).
 Mathematics — Lottery: The odds of winning the Jackpot (matching the 6 main numbers) in the UK National Lottery, with a single ticket, under the rules as of August 2009^{[update]}, are 13,983,815 to 1 against, for a probability of 7.15×10^{−8} (0.00000715%).
10^{−6}
(0.000001; 1000^{−2}; long and short scales: one millionth)
ISO: micro (μ)
 Mathematics – Poker: The odds of being dealt a royal flush in poker are 649,739 to 1 against, for a probability of 1.5 × 10^{−6} (0.00015%).
 Mathematics — Poker: The odds of being dealt a straight flush (other than a royal flush) in poker are 72,192 to 1 against, for a probability of 1.4 × 10^{−5} (0.0014%).
 Mathematics — Poker: The odds of being dealt a four of a kind in poker are 4,164 to 1 against, for a probability of 2.4 × 10^{−4} (0.024%).
10^{−3}
(0.001; 1000^{−1}; one thousandth)
ISO: milli (m)
 Mathematics — Poker: The odds of being dealt a full house in poker are 693 to 1 against, for a probability of 1.4 × 10^{−3} (0.14%).
 Mathematics — Poker: The odds of being dealt a flush in poker are 507.8 to 1 against, for a probability of 1.9 × 10^{−3} (0.19%).
 Mathematics — Poker: The odds of being dealt a straight in poker are 253.8 to 1 against, for a probability of 4 × 10^{−3} (0.39%).
 Physics: α = 0.007297352570(5), the finestructure constant.
10^{−2}
(0.01; one hundredth)
ISO: centi (c)
 Mathematics — Lottery: The odds of winning any prize in the UK National Lottery, with a single ticket, under the rules as of 2003, are 54 to 1 against, for a probability of about 0.018 (1.8%)
 Mathematics — Poker: The odds of being dealt a three of a kind in poker are 46 to 1 against, for a probability of 0.021 (2.1%)
 Mathematics — Lottery: The odds of winning any prize in the US Powerball Multistate Lottery, with a single ticket, under the rules as of 2006, are 36.61 to 1 against, for a probability of 0.027 (2.7%)
 Mathematics — Poker: The odds of being dealt two pair in poker are 20 to 1 against, for a probability of 0.048 (4.8%).
10^{−1}
(0.1; one tenth)
ISO: deci (d)
 Mathematics — Poker: The odds of being dealt only one pair in poker are about 5 to 2 against (2.37 to 1), for a probability of 0.42 (42%).
 Mathematics — Poker: The odds of being dealt no pair in poker are nearly 1 to 2, for a probability of about 0.5 (50%)
 Legal history: 10% was widespread as the tax raised for income or produce in the ancient and medieval period, see tithe.
10^{0}
(1; one)
 Religion: 1 God in monotheism
 Mathematics: √2 ≈ 1.414213562373095, the ratio of the diagonal of a square to its side length.
 Mathematics: φ ≈ 1.618033988749895, the golden ratio
 Mathematics: the number system understood by most computers, the binary system, uses 2 digits: 0 and 1.
 Mathematics: e ≈ 2.718281828459045, the base of the natural logarithm
 Mathematics: π ≈ 3.141592653589793, the ratio of a circle's circumference to its diameter
 BioMed: 7 ± 2, in cognitive science, George A. Miller's estimate of the number of objects that can be simultaneously held in human working memory
 Astronomy: 8 planets in the Solar System
10^{1}
(10; ten)
ISO: deca (da)
 Human scale: There are 10 fingers on a pair of human hands, and 10 toes on a pair of human feet.
 Mathematics: The number system used in everyday life, the decimal system, has 10 digits: 0,1,2,3,4,5,6,7,8,9.
 Mathematics: The hexadecimal system, a common number system used in computer programming, uses 16 digits where the last 6 are usually represented by letters: 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F.
 Science Fiction: The 23 enigma plays a prominent role in the plot of The Illuminatus! Trilogy by Robert Shea and Robert Anton Wilson.
 Alphabetic writing: There are 26 letters in the Latinderived English alphabet
 Science Fiction: The number 42, in the novel The Hitchhiker's Guide to the Galaxy by Douglas Adams, is the Answer to the Ultimate Question of Life, the Universe, and Everything which is calculated by an enormous supercomputer over a period of 7.5 million years. Unfortunately no one knows what the question is.
 Phonology: 47 phonemes in English phonology in Received Pronunciation
10^{2}
(100; hundred)
ISO: hecto (h)
 European history: Groupings of 100 homesteads was a common administrative unit in Northern Europe and Great Britain, see Hundred (county subdivision)
 Computing: There are 128 characters in the ASCII character set.
 Phonology: The Taa language is estimated to have between 130 and 164 distinct phonemes
 Political Science: There were 193 member states of the United Nations as of 2011.
10^{3}
(1000; thousand)
ISO: kilo (k)
 Typesetting: 2,000–3,000 letters on a typical typed page of text.
 Military history: 4,200 (Republic) or 5,200 (Empire) was the standard size of a Roman legion
 BioMed: the DNA of the simplest viruses has some 5,000 base pairs.
 Linguistics: Estimates for the linguistic diversity of living human languages or dialects range between 5,000 and 10,000 (SIL Ethnologue in 2007 listed 6,912 known living languages).
 Lexicography: 8,674 unique words in the Hebrew Bible
10^{4}
(10000; ten thousand or a myriad)
 BioMed: Each neuron in the human brain is estimated to connect to 10,000 others
 Lexicography: 14,500 unique English words occur in the King James Version of the Bible
 Language: There are 20,000–40,000 distinct Chinese characters, depending on how one counts them
 BioMed: Each human being is estimated to have 30,000 to 40,000 genes
 Mathematics: 65,537 is the largest known Fermat prime
 Memory: As of 2006^{[update]}, the largest number of decimal places of π that have been recited from memory is 67,890
10^{5}
(100000; one hundred thousand or a lakh)
 BioMed — Strands of hair on a head: The average human head has about 100,000–150,000 strands of hair
 Literature: approximately 100,000 verses (shlokas) in the Mahabharata
 Mathematics: 180,000 – The approximate number of entries in The OnLine Encyclopedia of Integer Sequences as of November 2010^{[update]}^{[5]}
 Language: 267,000 words in James Joyce's Ulysses
 Language — English words: The New Oxford Dictionary of English contains about 350,000 definitions for English words
 Literature: 564,000 words in War and Peace by Leo Tolstoy
 Literature: 930,000 words in the King James Version of the Bible
10^{6}
(1000000; 1000^{2}; long and short scales: one million)
ISO: mega (M)
 BioMed — Species: The World Resources Institute claims that approximately 1.4 million species have been named, out of an unknown number of total species (estimates range between 2 and 100 million species)
 Info: The freedb database of CD track listings has around 1,750,000 entries as of June 2005^{[update]}
 Mathematics — Playing cards: There are 2,598,960 different 5card poker hands that can be dealt from a standard 52card deck.
 Info — Web sites: As of November 2010, Wikipedia contains approximately 3,488,000 articles in the English language
 Geography/Computing — Geographic places: The NIMA GEOnet Names Server contains approximately 3.88 million named geographic features outside the United States, with 5.34 million names. The USGS Geographic Names Information System claims to have almost 2 million physical and cultural geographic features within the United States.
 Genocide: Approximately 5,100,000–6,200,000 Jews were killed in the Holocaust.
10^{7}
(10000000; a crore; long and short scales: ten million)
 Mathematics: 12,988,816 is the number of domino tilings of an 8×8 checkerboard.
 Computing: 16,777,216 different colors can be generated using the hex code system in HTML (It has been estimated that the trichromatic color vision of the human eye can only distinguish about 1,000,000 different colors.).
 Science Fiction: In Isaac Asimov's Galactic Empire, in what we call 22,500 CE there are 25,000,000 different inhabited planets in the Galactic Empire, all inhabited by humans in Asimov's "human galaxy" scenario.
10^{8}
(100000000; long and short scales: one hundred million)
 Info — Books: The British Library claims that it holds over 150 million items. The Library of Congress claims that it holds approximately 119 million items. See The Gutenberg Galaxy
 Info — Web sites: As of June 2010^{[update]}, the Netcraft web survey estimates that there are 206,956,723 (206 million) distinct websites.
 Mathematics: More than 215,000,000 mathematical constants are collected on the Plouffe's Inverter as of 2010^{[update]}^{[6]}
 Mathematics: 275,305,224 is the number of 5x5 normal magic squares, not counting rotations and reflections. This result was found in 1973 by Richard Schroeppel. It is the third 91768409gonal number.
 Mathematics: 358,833,097 stellations of the rhombic triacontahedron
 Demographics: Approximately 402,000,000 native speakers of English
 Internet: Approximately 500,000,000 active users are on Facebook as of March 2010
 Astronomy — Cataloged stars: The Guide Star Catalog II has entries on 998,402,801 distinct astronomical objects
10^{9}
(1000000000; 1000^{3}; short scale: one billion; long scale: one thousand million, or one milliard)
ISO: giga (G)
 Demographics — India: 1,096,000,000 – approximate population of India in 2007
 Demographics — China: 1,311,000,000 – approximate population of the People's Republic of China in 2007.
 Computing — Computational limit of a 32bit CPU: 2 147 483 647 is equal to 2^{31}−1, and as such is the largest number which can fit into a signed (two's complement) 32bit integer on a computer, thus marking the upper computational limit of a 32bit CPU such as Intel's Pentiumclass computer chips.
 BioMed — base pairs in the genome: approximately 3×10^{9} base pairs in the human genome
 Linguistics: 3,400,000,000 – the total number of speakers of IndoEuropean languages, of which 2,400,000,000 are native speakers; the other 1,000,000,000 speak IndoEuropean languages as a second language
 Computing – IPv4: 4,294,967,296 (2^{32}) possible unique IP addresses.
 Computing: 4,294,967,296 – the number of bytes in 4 gibibytes; in computation, the 32bit computers can directly access 2^{32} pieces of address space, this leads directly to the 4 gigabyte limit on main memory.
 Mathematics: 4,294,967,297 is a Fermat number and semiprime. It is the smallest number of the form which is not a prime number.
 Demographics — world population: 7,000,000,000 – Estimated population for the world on 31 October 2011, the Day of Seven Billion.
10^{10}
(10000000000; short scale: ten billion; long scale: ten thousand million, or ten milliard)
 BioMed — bacteria in the human body: There are roughly 10^{10} bacteria in the human oral cavity^{[7]}
 Astronomy — Observable galaxies: as of 2003 there are between 1×10^{10} and 8×10^{10} galaxies in the observable universe
 Computing — web pages: approximately 5.6×10^{10} web pages indexed by Google as of 2010.
10^{11}
(100000000000; short scale: one hundred billion; long scale: hundred thousand million, or hundred milliard)
 BioMed — Neurons in the brain: approximately 10^{11} neurons in the human brain
 Paleodemography: approximately 1.06 × 10^{11} individuals of Homo sapiens have lived since speciation (40% of this figure are babies who did not live beyond their first year) (see world population).
 Astronomy — stars in our galaxy: approximately 4×10^{11} stars in the Milky Way galaxy (Often the figure 1×10^{11} is quoted in error; that is the total mass of the galaxy in solar masses. However, the total number of stars in the galaxy is 4×10^{11} because 73% of the stars in the galaxy are red dwarves, which have a much smaller mass than the Sun.)
10^{12}
(1000000000000; 1000^{4}; short scale: one trillion; long scale: one billion)
ISO: tera (T)
 Astronomy: Andromeda Galaxy, which is part of the same Local Group as our galaxy, contains about 10^{12} stars.
 BioMed — Bacteria on the human body: The surface of the human body houses roughly 10^{12} bacteria.^{[7]}
 Marine biology: 3,500,000,000,000 (3.5 × 10^{12}) – estimated population of fish in the ocean.
 Mathematics — Known digits of π: As of 2010^{[update]}, the number of known digits of π is 5,000,000,000,000 (5×10^{12}).^{[8]}
 Mathematics: 7,625,597,484,987 – a number that often appears when dealing with powers of 3. It can be expressed as 19683^{3}, 27^{9}, 3^{27}, and ^{3}3 or when using Knuth's uparrow notation it can be expressed as and .
 Mathematics: 10^{13} – The approximate number of known nontrivial zeros of the Riemann zeta function as of 2004^{[update]}.^{[9]}
 BioMed — Cells in the human body: The human body consists of roughly 10^{14} cells, of which only 10^{13} are human.^{[10]}^{[11]} The remaining 90% nonhuman cells (though much smaller and constituting much less mass) are bacteria, which mostly reside in the gastrointestinal tract, although the skin is also covered in bacteria.
 Computing – MAC48: 281,474,976,710,656 (2^{48}) possible unique physical addresses.
 Mathematics: 953,467,954,114,363 is the largest known Motzkin prime.
10^{15}
(1000000000000000; 1000^{5}; short scale: one quadrillion; long scale: one thousand billion, or one billiard)
ISO: peta (P)
 BioMedInsects: 1,000,000,000,000,000 to 10,000,000,000,000,000 (10^{15} to 10^{16}) – The estimated total number of ants on Earth alive at any one time (their biomass is approximately equal to the total biomass of the human race).^{[12]}
 Computing: 9,007,199,254,740,992 (2^{53}) – number until which all integer values can exactly be represented in IEEE double precision floatingpoint format.
 Mathematics: 48,988,659,276,962,496 is the fifth taxicab number.
 Science Fiction: In Isaac Asimov's Galactic Empire, in what we call 22,500 CE there are 25,000,000 different inhabited planets in the Galactic Empire, all inhabited by humans in Asimov's "human galaxy" scenario, each with an average population of 2,000,000,000, thus yielding a total Galactic Empire population of approximately 50,000,000,000,000,000.
 Cryptography: There are 7.205759×10^{16} different possible keys in the obsolete 56 bit DES symmetric cipher.
10^{18}
(1000000000000000000; 1000^{6}; short scale: one quintillion; long scale: one trillion)
ISO: exa (E)
 Computing — Manufacturing: An estimated 6×10^{18} transistors were produced worldwide in 2008.^{[13]}
 Computing — Computational limit of a 64bit CPU: 9,223,372,036,854,775,807 (about 9.22×10^{18}) is equal to 2^{63}1, and as such is the largest number which can fit into a signed (two's complement) 64bit integer on a computer.
 Mathematics — NCAA Basketball Tournament: There are 9,223,372,036,854,775,808 (2^{63}) possible ways to enter the bracket.
 Mathematics — Bases: 9,439,829,801,208,141,318 is the 10th and largest number with more than one digit that can be written from base 2 to base 18 using only the digits 0 to 9.^{[14]}
 BioMed — Insects: It has been estimated that the insect population of the Earth is about 10^{19}.^{[15]}
 Mathematics — Answer to the wheat and chessboard problem: When doubling the grains of wheat on each successive square of a chessboard, beginning with one grain of wheat on the first square, the final number of grains of wheat on all 64 squares of the chessboard when added up is 2^{64}−1 = 18,446,744,073,709,551,615.
 Mathematics — Legends: In the legend called the Tower of Brahma about a Hindu temple which contains a large room with three posts on one of which is 64 golden discs, the object of the mathematical game is for the Brahmins in the temple to move all of the discs to another pole so that they are in the same order, never placing a larger disc above a smaller disc. It would take 2^{64}−1 = 18,446,744,073,709,551,615 turns to complete the task (same number as the wheat and chessboard problem above).^{[16]}
 Mathematics — Rubik's Cube: There are 43,252,003,274,489,856,000 (about 43×10^{18}) different positions of a 3x3x3 Rubik's Cube
 Password strength: Usage of the 95character set found on standard computer keyboards for a 10character password yields a computationally intractable 59,873,693,923,837,890,625 (95^{10}, approximately 6×10^{19}) permutations.
 Economics: Hyperinflation in Zimbabwe estimated in February 2009 by some economists at 10 sextillion percent,^{[17]} or a factor of 10^{20}
10^{21}
(1000000000000000000000; 1000^{7}; short scale: one sextillion; long scale: one thousand trillion, or one trilliard)
ISO: zetta (Z)
 Geo — Grains of sand: all the world's beaches put together have been estimated to hold roughly 10^{21} grains of sand.^{[18]}
 Mathematics — Sudoku: There are 6,670,903,752,021,072,936,960 (≈6.7×10^{21}) 9×9 sudoku grids.^{[19]}
 Astronomy — Stars: 70 sextillion = 7×10^{22} estimated number of stars within range of telescopes (as of 2003), see mass of the observable universe.^{[20]}
 Mathematics: 146,361,946,186,458,562,560,000 (≈1.5×10^{23}) is the fifth unitary perfect number.
 Chemistry: there are roughly 6.022×10^{23} molecules in one mole of any substance (Avogadro's number)
10^{24}
(1000000000000000000000000; 1000^{8}; short scale: one septillion; long scale: one quadrillion)
ISO: yotta (Y)
 Mathematics: 2,833,419,889,721,787,128,217,599 (≈2.8×10^{24}) is a Woodall prime.
10^{27}
(1000000000000000000000000000; 1000^{9}; short scale: one octillion; long scale: one thousand quadrillion, or one quadrilliard)
 BioMed — Atoms in the human body: the average human body contains roughly 7×10^{27} atoms^{[21]}
 Mathematics — Poker: the number of unique combinations of hands and shared cards in a 10player game of Texas Hold'em is approximately 2.117×10^{28}, see Poker probability (Texas hold 'em).
10^{30}
(1000000000000000000000000000000; 1000^{10}; short scale: one nonillion; long scale: one quintillion)
 BioMed — Bacterial cells on Earth: The number of bacterial cells on Earth is estimated at around 5,000,000,000,000,000,000,000,000,000,000, or 5 × 10^{30} ^{[22]}
 Mathematics: The partition of 1000 is 24,061,467,864,032,622,473,692,149,727,991.^{[23]}
 Mathematics: 2^{108} = 324,518,553,658,426,726,783,156,020,576,256 is the last known power of two not containing a digit '9'.^{[24]}
10^{33}
(1000000000000000000000000000000000; 1000^{11}; short scale: one decillion; long scale: one thousand quintillion, or one quintilliard)
 Mathematics — Alexander's Star: There are 72,431,714,252,715,638,411,621,302,272,000,000 (about 7.24×10^{34}) different positions of Alexander's Star
10^{36}
(1000000000000000000000000000000000000; 1000^{12}; short scale: one undecillion; long scale: one sextillion)
 Physics: k_{e}e^{2} / Gm^{2}, the ratio of the electromagnetic to the gravitational forces between two protons, is roughly 10^{36}.
 Mathematics: = 170,141,183,460,469,231,731,687,303,715,884,105,727 (≈1.7×10^{38}) is a double Mersenne prime.
 Computing: (2^{128} = 340,282,366,920,938,463,463,374,607,431,768,211,456 (≈3.40282367×10^{38}), the theoretical maximum number of Internet addresses that can be allocated under the IPv6 addressing system, one more than the largest value that can be represented by a singleprecision IEEE floatingpoint value, the total number of different Universally Unique Identifiers (UUIDs) that can be generated.
 Cryptography: 2^{128} = 340,282,366,920,938,463,463,374,607,431,768,211,456 (≈3.40282367×10^{38}), the total number of different possible keys in the AES 128bit key space (symmetric cipher).
10^{39}
(1000000000000000000000000000000000000000; 1000^{13}; short scale: one duodecillion; long scale: one thousand sextillion, or one sextilliard)
 Cosmology: The Eddington–Dirac number is roughly 10^{40}.
 Mathematics: 69,720,375,229,712,477,164,533,808,935,312,303,556,800 (≈7.0×10^{40}) is the least common multiple of every integer from 1 to 100.
10^{42} to 10^{100}
(1000000000000000000000000000000000000000000; 1000^{14}; short scale: one tredecillion; long scale: one septillion)
 Mathematics: 141×2^{141}+1 = 393,050,634,124,102,232,869,567,034,555,427,371,542,904,833 (≈3.9×10^{44}) is the second Cullen prime
 Mathematics: There are 7,401,196,841,564,901,869,874,093,974,498,574,336,000,000,000 (≈7.4×10^{45}) possible permutations for the Rubik's Revenge (4x4x4 Rubik's Cube).
 Chess: 4.52×10^{46} is a proven upper bound for the number of legal chess positions.^{[25]}
 Mathematics: 808,017,424,794,512,875,886,459,904,961,710,757,005,754,368,000,000,000 (≈8×10^{53}) is the order of the Monster group.
 Cryptography: There are 6.27710174×10^{57} different possible keys in the AES 192 bit key space (symmetric cipher).
 Cosmology: 8×10^{60} is roughly the number of Planck time intervals since the universe is theorised to have been created in the Big Bang 13.7 ± 0.2 billion years ago.
 Cosmology: 1×10^{63} is Archimedes’ estimate in The Sand Reckoner of the total number of grains of sand that could fit into the entire cosmos, the diameter of which he estimated to be what we call 2 light years.
 Mathematics — Cards: 52! = 80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000 (≈8×10^{67}) – the number of ways to order the cards in a 52card deck.
 Mathematics: 1,808,422,353,177,349,564,546,512,035,512,530,001,279,481,259,854,248,860,454,348,989,451,026,887 (≈1.8×10^{72}) – The largest known prime factor found by ECM factorization as of 2010^{[update]}.^{[26]}
 Mathematics: There are 282 870 942 277 741 856 536 180 333 107 150 328 293 127 731 985 672 134 721 536 000 000 000 000 000 (2.8287×10^{74}) possible permutations for the Professor's Cube (5x5x5 Rubik's Cube).
 Cryptography: There are 1.15792089×10^{77} different possible keys in the AES 256 bit keyspace (symmetric cipher).
 Cosmology: Various sources estimate the total number of fundamental particles in the observable universe to be within in the range of 10^{80} to 10^{85}. However, these estimates are generally regarded as guesswork.
 Mathematics: 10 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000; 10^{100}, a googol
10^{100} (one googol) to (one googolplex)
 Mathematics: There are 157 152 858 401 024 063 281 013 959 519 483 771 508 510 790 313 968 742 344 694 684 829 502 629 887 168 573 442 107 637 760 000 000 000 000 000 000 000 000 (1.5715 ×10^{116}) distinguishable permutations of the VCube 6 (6x6x6 Rubik's Cube).
 Chess: Shannon number, 10^{120}, an estimation of the gametree complexity of chess.
 Physics: 8×10^{120}, ratio of the massenergy in the observable universe to the energy of a photon with a wavelength the size of the observable universe.
 History — Religion: Asaṃkhyeya is a Buddhist name for the number 10^{140}. It is listed in the Avatamsaka Sutra and metaphorically means "innumerable" in the Sanskrit language of ancient India.
 Xiangqi: 10^{150}, an estimation of the gametree complexity of xiangqi.
 Mathematics: There are 19 500 551 183 731 307 835 329 126 754 019 748 794 904 992 692 043 434 567 152 132 912 323 232 706 135 469 180 065 278 712 755 853 360 682 328 551 719 137 311 299 993 600 000 000 000 000 000 000 000 000 000 000 000 (1.9501 ×10^{160}) distinguishable permutations of the VCube 7 (7x7x7 Rubik's Cube).
 Board games: 3.457×10^{181}, number of ways to arrange the tiles in English Scrabble on a standard 15by15 Scrabble board.
 Physics: 4×10^{185}, approximate number of Planck volumes in the observable universe.
 Computing: 1.797 693 134 862 3157×10^{308} is approximately equal to the largest value that can be represented in the IEEE double precision floatingpoint format.
 Go: 10^{365}, an estimation of the gametree complexity in the game of Go.^{[citation needed]}
 Mathematics: 2638^{4405} + 4405^{2638} is a 15,071digit Leyland prime; the largest which has been proven as of 2010^{[update]}.^{[27]}
 Mathematics: 183,027 × 2^{265,440}−1 is a 79,911digit Sophie Germain prime; the largest known as of March 2010^{[update]}.^{[28]}
 Mathematics: 65,516,468,355 · 2^{333,333} ± 1 are 100,355digit twin primes; the largest known as of 2010^{[update]}.^{[29]}
 Mathematics: 10^{200000} + 47960506974×10^{99995} + 1 is a 200,001digit palindromic prime, the largest known as of December 2010^{[update]}.^{[30]}
 Mathematics: approximately 7.76 · 10^{206,544} cattle in the smallest herd which satisfies the conditions of the Archimedes' cattle problem.
 Mathematics: 843,301# – 1 is a 365,851digit primorial prime; the largest known as of 2010^{[update]}.^{[31]}
 Mathematics: 110,059! + 1 is a 507,082digit factorial prime; the largest known as of June 2011^{[update]}.^{[32]}
 Mathematics: 145,310^{262,144} + 1 is a 1,353,265digit Generalized Fermat prime, the largest known as of 2011^{[update]}.^{[33]}
 Mathematics — Literature: Jorge Luis Borges' Library of Babel contains at least books (this is a lower bound).^{[34]}
 Mathematics: 19,249 × 2^{13,018,586} + 1 is a 3,918,990digit Proth prime, the largest known Proth prime^{[35]} and nonMersenne prime as of 2010^{[update]}.^{[36]}
 Mathematics: 2^{43,112,609} − 1 is a 12,978,189digit Mersenne prime; the largest known prime of any kind as of 2010^{[update]}.^{[36]}
 Mathematics: 2^{43,112,608} × (2^{43,112,609} − 1) is a 25,956,377digit perfect number, the largest known as of 2010.^{[37]}
 Mathematics — History: 10^{80,000,000,000,000,000}, largest named number in Archimedes' Sand Reckoner.
 Mathematics: 10^{googol} (), a googolplex.
Larger than (one googolplex)
 Cosmology: In chaotic inflation theory, proposed by physicist Andrei Linde, our universe is one of many other universes with different physical constants that originated as part of our local section of the multiverse, owing to a vacuum that had not decayed to its ground state. According to Linde and Vanchurin, the total number of these universes is about .^{[38]}
 Mathematics—Literature: The number of different ways in which the books in Luis Borges' Library of Babel can be arranged is .^{[39]}^{[40]}
 Mathematics: , order of magnitude of an upper bound that occurred in a proof of Skewes (later estimated to actually be near 1.397 × 10^{316}).
 Mathematics: , order of magnitude of another upper bound in a proof of Skewes.
 Mathematics: Moser's number "2 in a megagon" is approximately equal to 10↑↑↑...↑↑↑10, where there are 10↑↑257 arrows.
 Mathematics: Graham's number, the last ten digits of which are ...24641 95387. Arises as an upper bound solution to a problem in Ramsey theory. Representation in powers of 10 would be impractical (the number of digits in the exponent far exceeds the number of particles in the observable universe).
 Mathematics: TREE(3): appears in relation to a theorem on trees in graph theory. Representation of the number is difficult, but one weak lower bound is A^{A(187196)}(1), where A(n) is a version of the Ackermann function.
See also
 Large numbers
 Conway chained arrow notation
 Fastgrowing hierarchy
 Names of large numbers
 Names of small numbers
 List of numbers
 Planck units
 Mathematical constant
 Encyclopedic size comparisons on Wikipedia
References
 ^ Kittel, Charles and Herbert Kroemer (1980). Thermal Physics (2nd ed.). W. H. Freeman Company. pp. 53. ISBN 0716710889.
 ^ There are around 130,000 letters and 199,749 total characters in Hamlet; 26 letters ×2 for capitalization, 12 for punctuation characters = 64, 64^{199749} ≈ 10^{360,783}.
 ^ Bridge hands
 ^ P. L. Walraven and H. J. Lebeek. "Foveal Sensitivity of the Human Eye in the Near Infrared". J. Opt. Soc. Am. 53, 765–766 (1963).
 ^ The OnLine Encyclopedia of Integer Sequences
 ^ Plouffe's Inverter
 ^ ^{a} ^{b} "Earth microbes on the moon". Science@Nasa. 1 September 1998. http://science.nasa.gov/newhome/headlines/ast01sep98_1.htm. Retrieved 2 November 2010.
 ^ Alexander J. Yee & Shigeru Kondo (2 August 2010). "5 Trillion Digits of Pi – New World Record". http://www.numberworld.org/misc_runs/pi5t/announce_en.html. Retrieved 2 November 2010.
 ^ Xavier Gourdon (October 2004). "Computation of zeros of the Zeta function". http://numbers.computation.free.fr/Constants/Miscellaneous/zetazeroscompute.html. Retrieved 2 November 2010.
 ^ Savage, D. C. (1977). "Microbial Ecology of the Gastrointestinal Tract". Annual Review of Microbiology 31: 107. doi:10.1146/annurev.mi.31.100177.000543. PMID 334036
 ^ Berg, R. (1996). "The indigenous gastrointestinal microflora". Trends in Microbiology 4: 430. doi:10.1016/0966842X(96)100573. PMID 8950812
 ^ Bert Holldobler and E.O. Wilson The Superorganism: The Beauty, Elegance, and Strangeness of Insect Societies New York:2009 W.W. Norton Page 5
 ^ SIA Hails "60th Birthday of Microelectronics Industry". Semiconductor Industry Association. 13 December 2007. http://www.siaonline.org/cs/papers_publications/press_release_detail?pressrelease.id=96 SIA Hails. Retrieved 2 November 2010.
 ^ Sequence A131646 in The OnLine Encyclopedia of Integer Sequences
 ^ "Frequently Asked Questions on Entomology". Entomological Society of America.
 ^ Ivan Moscovich, 1000 playthinks: puzzles, paradoxes, illusions & games, Workman Pub., 2001 ISBN 0761118268.
 ^ "Scores of Zimbabwe farms 'seized'". BBC. 23 February 2009. http://news.bbc.co.uk/1/hi/world/africa/7906031.stm. Retrieved 14 March 2009.
 ^ To see the Universe in a Grain of Taranaki Sand
 ^ Sudoku enumeration
 ^ "Star count: ANU astronomer makes best yet". The Australian National University. 17 July 2003. http://msowww.anu.edu.au/news/media_releases/media_release_030717.php. Retrieved 2 November 2010.
 ^ How many atoms are in the human body?
 ^ William B. Whitman, David C. Coleman, William J. Wiebe (1998). "Prokaryotes: The unseen majority". Proceedings of the National Academy of Sciences of the United States of America 95 (12): 6578–6583. doi:10.1073/pnas.95.12.6578. PMC 33863. PMID 9618454. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=33863.
 ^ (sequence A070177 in OEIS)
 ^ (sequence A035064 in OEIS)
 ^ John Tromp (2010). "John's Chess Playground". http://www.cwi.nl/~tromp/chess/chess.html.
 ^ Paul Zimmermann, "50 largest factors found by ECM".
 ^ Chris Caldwell, The Top Twenty: Elliptic Curve Primality Proof at The Prime Pages.
 ^ Chris Caldwell, The Top Twenty: Sophie Germain (p) at The Prime Pages.
 ^ Chris Caldwell, The Top Twenty: Twin Primes at The Prime Pages.
 ^ Chris Caldwell, The Top Twenty: Palindrome at The Prime Pages.
 ^ PrimeGrid's Primorial Prime Search
 ^ Chris Caldwell, The Top Twenty: Factorial primes at The Prime Pages.
 ^ Chris Caldwell, The Top Twenty: Generalized Fermat at The Prime Pages.
 ^ From the third paragraph of the story: "Each book contains 410 pages; each page, 40 lines; each line, about 80 black letters." That makes 410 x 40 x 80 = 1,312,000 characters. The fifth paragraph tells us that "there are 25 orthographic symbols" including spaces and punctuation. The magnitude of the resulting number is found by taking logarithms. However, this calculation only gives a lower bound on the number of books as it does not take into account variations in the titles – the narrator does not specify a limit on the number of characters on the spine. For further discussion of this, see Bloch, William Goldbloom. The Unimaginable Mathematics of Borges' Library of Babel. Oxford University Press: Oxford, 2008.
 ^ Chris Caldwell, The Top Twenty: Proth at The Prime Pages.
 ^ ^{a} ^{b} Chris Caldwell, The Top Twenty: Largest Known Primes at The Prime Pages.
 ^ Chris Caldwell, Mersenne Primes: History, Theorems and Lists at The Prime Pages.
 ^ Zyga, Lisa "Physicists Calculate Number of Parallel Universes", PhysOrg, 16 October 2009.
 ^ American Scientist January–February 2009 BooksaMillion by Brian Hayes Book Review of The Unimaginable Mathematics of Borges’ Library of Babel by William Goldbloom Bloch:
 ^ Bloch, William Goldbloom The Unimaginable Mathematics of Borges’ Library of Babel (2008) Oxford University Press
External links
 Seth Lloyd's paper Computational capacity of the universe provides a number of interesting dimensionless quantities.
 Notable properties of specific numbers
Orders of magnitude Quantity acceleration · angular velocity · area · charge · computing · currency · data · density · energy · entropy · force · frequency · length · luminous flux · magnetic field · mass · numbers · power · pressure · radiation · resistance · specific energy density · specific heat capacity · speed · temperature · time · voltage · volumeSee also Categories: Orders of magnitude
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