- 85 (number)
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85 (eighty-five) is the natural number following 84 and preceding 86.
85 Cardinal eighty-five Ordinal 85th
(eighty-fifth)Numeral system 85 Factorization Divisors 1, 5, 17, 85 Roman numeral LXXXV Binary 10101012 Octal 1258 Duodecimal 7112 Hexadecimal 5516 Contents
In mathematics
85 is an octahedral number, a centered triangular number, a centered square number, a decagonal number, and a Smith number.
85 is the product of two prime numbers (5 and 17), and is therefore a biprime; specifically, the 24th biprime not counting perfect squares. Together with 86 and 87, it forms the second cluster of three consecutive biprimes.
85 can be expressed as a sum of two squares in two ways, 85= 92 + 22 = 72 + 62
85 is 1111 (a repunit) in base 4; which is expected, since its two factors 5 and 17 are consecutive Fermat primes, and the base 4 is one less than the smaller factor 5.
The aliquot sum of 85 is 23 within the aliquot sequence (23,1,0) 85 being the second composite number in the 23-aliquot tree.
In astronomy
- Messier object M85 is a magnitude 10.5 lenticular galaxy in the constellation Coma Berenices
- NGC 85 is a galaxy in the constellation Andromeda
- 85 Io is a large main belt asteroid
- 85 Pegasi is a multiple star system in constellation of Pegasus
- 85 Ceti is a variable star in the constellation of Cetus
- 85P/Boethin is a periodic comet
- 85 is the Saros number of the solar eclipse series which began on -170 March 14 and ended on 1110 April (1280.1 years, 72 solar eclipses)
- 85 is also the Saros number of the lunar eclipse series which began on -103 August 2 and ended on 1267 November (1370.3 years, 77 lunar eclipses)
In titles and names
- Federalist No. 85, by Alexander Hamilton, the last of the Federalist Papers' (1788)
- The 85 Ways to Tie a Tie, a book by Thomas Fink and Yong Mao
- 85 Days: The Last Campaign of Robert Kennedy a book by Jules Witcover
- Live/1975–85, an album of live reordings by Bruce Springsteen (1986)
- 80–85 a compilation album by Bad Religion (1991)
- Cupid & Psyche 85, an album by band Scritti Politti (1985)
- 45/85 was a television documentary on World War II
- Minuscule 85, Papyrus 85, Lectionary 85 are early Greek manuscripts of the New Testament
- "85", a 2000 rap single by YoungBloodz, from their album Against Da Grain
- 85°C, a Taiwanese coffee store chain.
In sports
In U.S. college athletics, schools that are members of NCAA Division I are limited to providing athletic scholarships to a maximum of 85 football players in a given season. The specifics vary by the two Division I football subdivisions:
- In the top-level FBS, each player provided with a scholarship may, and almost always does, receive a full scholarship.
- In the second-level FCS, schools are allowed to provide football-related athletic aid equivalent to 63 full scholarships, but this aid may be divided among up to 85 players as the schools see fit.
In other fields
Eighty-five is also:
- The year AD 85, 85 BC, or 1985.
- The Muslim calendar year 85 AH.
- The atomic number of astatine
- The number of the French department Vendée
- The ISBN Group Identifier for books published in Brazil
- The radix of the Ascii85 (sometimes called Base85) binary-to-text encoding
- The IQ and nickname of Aaron in Alien 3
- The number worn by Chad Ochocinco, whose name means "eight five" in Spanish
Moreover:
- Arabigere 85 is a village in India
- E85 fuel is 85% ethanol and 15% conventional gasoline
- MCS-85 was a family of Intel processors including the 8085
- TI-85 was a graphing pocket calculator by Texas Instruments
- KC 85 was a family of small computers built in East Germany in the 1980s
- PMD 85 was a personal computer built in Czechoslovakia in 1985
- Learjet 85 is an all-composite plane being developed by Bombardier Aerospace
- British Rail Class 85, a category of UK train locomotives
- DRG Class 85, a category of German train locomotives
- TK 85 was a clone of the Sinclair ZX81 made in Brazil in 1895
- Lima Site 85 was a battle in the Vietnam War
- A85 is the Dutch Defence in the Encyclopaedia of Chess
- EF 85mm is a photographic camera lens by Canon
- F-85 is a family of Oldsmobile cars
In military technology
- 85mm is a common caliber for cannons
- SU-85 was a Soviet tank
- TR-85 was a Romanian battle tank
- Tu-85 was a prototype Soviet bomber
- ASU-85 a Soviet self-propelled gun
- CZ 85 is a Czech 9mm semiautomatic pistol
- PT-85 is a Korean tank
- 7.62 Tkiv 85 is a Finnish army rifle
- HG 85 is a Swiss fragmentation grenade
- Taurus Model 85, a 9mm revolver made in Brazil
See also
- List of highways numbered 85
- List of highways numbered 85A
- Type 85, a designation of many military equipment
External links
- 85
- Jorge Stolfi, The Hollywood Constant.
Categories:- Integers
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