2000 (number)

2000 (two thousand) is the natural number following 1999 and preceding 2001.

See also: millennium, year 2000 AD, Y2K, 2000 (disambiguation).

Two thousand is the highest number expressible using only two unmodified characters in roman numerals (MM).

Two thousand is also:
* In the name of the products Lever 2000 and Grecian 2000, Windows 2000
* In "Star Trek", the registry number of the USS Excelsior, NX-2000 in "Star Trek III: The Search for Spock", and NCC-2000 commanded by Hikaru Sulu in "Star Trek VI: The Undiscovered Country".
* The postal code for Antwerp (Belgium) and Sydney (Australia)

Selected numbers in the range 2001-2999

* 2001 - sphenic number
* 2003 - Sophie Germain prime
* 2007 - Last year (Gregorian Calendar)
* 2008 - Current year (Gregorian Calendar)
* 2009 - Next year (Gregorian Calendar)
* 2015 - Lucas-Carmichael number
* 2016 - triangular number
* 2017 - Mertens function zero
* 2020 - sum of the totient function for the first 81 integers
* 2024 - tetrahedral number
* 2025 - $45^2$, sum of the cubes of the first nine integers, centered octagonal number
* 2027 - safe prime
* 2029 - member of the Mian-Chowla sequence
* 2030 - $21^2\; +\; 22^2\; +\; 23^2\; +\; 24^2$, $25^2\; +\; 26^2\; +\; 27^2$
* 2031 - centered pentagonal number
* 2039 - Sophie Germain prime, safe prime
* 2047 - super-Poulet number, Woodall number, decagonal number
* 2048 - power of two
* 2056 - magic constant of "n"×"n" normal magic square and "n"-Queens Problem for "n" = 16.
* 2060 - sum of the totient function for the first 82 integers
* 2063 - Sophie Germain prime, safe prime
* 2069 - Sophie Germain prime
* 2070 - pronic number
* 2080 - triangular number
* 2093 - Mertens function zero
* 2095 - Mertens function zero
* 2096 - Mertens function zero
* 2097 - Mertens function zero
* 2099 - Mertens function zero, safe prime, highly cototient number
* 2100 - Mertens function zero
* 2101 - centered heptagonal number
* 2107 - member of a Ruth-Aaron pair with 2108 (first definition)
* 2108 - member of a Ruth-Aaron pair with 2107 (first definition)
* 2109 - square pyramidal number
* 2112 - The break-through album of the band Rush
* 2113 - Mertens function zero, Proth prime
* 2116 - $46^2$
* 2117 - Mertens function zero
* 2119 - Mertens function zero
* 2120 - Mertens function zero
* 2122 - Mertens function zero
* 2125 - nonagonal number
* 2127 - sum of the first 34 primes
* 2129 - Sophie Germain prime
* 2135 - Mertens function zero
* 2136 - Mertens function zero
* 2138 - Mertens function zero
* 2141 - Sophie Germain prime
* 2142 - sum of the totient function for the first 83 integers
* 2145 - triangular number
* 2162 - pronic number
* 2166 - sum of the totient function for the first 84 integers
* 2169 - Leyland number
* 2171 - Mertens function zero
* 2172 - Mertens function zero
* 2175 - smallest number requiring 143 seventh powers for Waring representation
* 2176 - pentagonal pyramidal number, centered pentagonal number
* 2179 - Wedderburn-Etherington number
* 2187 - $3^7$, vampire number, perfect totient number
* 2188 - Motzkin number
* 2197 - $13^3$
* 2199 - perfect totient number
* 2205 - odd abundant number
* 2207 - safe prime, Lucas prime
* 2208 - Keith number
* 2209 - $47^2$, centered octagonal number
* 2211 - triangular number
* 2223 - Kaprekar number
* 2230 - sum of the totient function for the first 85 integers
* 2232 - decagonal number
* 2254 - member of the Mian-Chowla sequence
* 2255 - octahedral number
* 2256 - pronic number
* 2269 - cuban prime
* 2272 - sum of the totient function for the first 86 integers
* 2273 - Sophie Germain prime
* 2276 - sum of the first 35 primes, centered heptagonal number
* 2278 - triangular number
* 2287 - balanced prime
* 2294 - Mertens function zero
* 2295 - Mertens function zero
* 2296 - Mertens function zero
* 2299 - member of a Ruth-Aaron pair with 2300 (first definition)
* 2300 - tetrahedral number, member of a Ruth-Aaron pair with 2299 (first definition)
* 2301 - nonagonal number
* 2304 - $48^2$
* 2306 - Mertens function zero
* 2309 - primorial prime, Mertens function zero, highly cototient number
* 2310 - 5th primorial
* 2311 - primorial prime
* 2321 - Mertens function zero
* 2322 - Mertens function zero
* 2326 - centered pentagonal number
* 2328 - sum of the totient function for the first 87 integers, the number of groups of order 128, see [http://www-public.tu-bs.de:8080/~beick/soft/small/small.html] .

* 2331 - centered cube number
* 2338 - Mertens function zero
* 2339 - Sophie Germain prime
* 2346 - triangular number
* 2351 - Sophie Germain prime
* 2352 - pronic number
* 2357 - Smarandache-Wellin prime
* 2368 - sum of the totient function for the first 88 integers
* 2378 - Pell number
* 2379 - member of the Mian-Chowla sequence
* 2393 - Sophie Germain prime
* 2397 - sum of the squares of the first ten primes
* 2399 - Sophie Germain prime
* 2400 - perfect score on SAT tests administered after 2005
* 2401 - $7^4$, $49^2$, centered octagonal number
* 2415 - triangular number
* 2417 - balanced prime
* 2425 - decagonal number
* 2427 - sum of the first 36 primes
* 2437 - cuban prime
* 2447 - safe prime
* 2450 - pronic number
* 2456 - sum of the totient function for the first 89 integers
* 2458 - centered heptagonal number
* 2459 - Sophie Germain prime, safe prime
* 2465 - magic constant of "n"×"n" normal magic square and "n"-Queens Problem for "n" = 17, Carmichael number
* 2470 - square pyramidal number
* 2480 - sum of the totient function for the first 90 integers
* 2481 - centered pentagonal number
* 2484 - nonagonal number
* 2485 - triangular number
* 2491 - member of Ruth-Aaron pair with 2492 under second definition
* 2492 - member of Ruth-Aaron pair with 2491 under second definition
* 2500 - $50^2$
* 2501 - Mertens function zero
* 2502 - Mertens function zero
* 2510 - member of the Mian-Chowla sequence
* 2513 - member of the Padovan sequence
* 2517 - Mertens function zero
* 2519 - the smallest number when divided by 10 gives a remainder 9; when divided by 9 gives a remainder 8; when divided by 7 gives a remainder 6; and so on until when divided by 2 gives a remainder 1
* 2520 - highly composite number; smallest number divisible by numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, & 12 ; colossally abundant number; Harshad number in several bases.
* 2522 - Mertens function zero
* 2523 - Mertens function zero
* 2524 - Mertens function zero
* 2525 - Mertens function zero
* 2530 - Mertens function zero, Leyland number
* 2533 - Mertens function zero
* 2537 - Mertens function zero
* 2538 - Mertens function zero
* 2543 - Sophie Germain prime
* 2549 - Sophie Germain prime
* 2550 - pronic number
* 2552 - sum of the totient function for the first 91 integers
* 2556 - triangular number
* 2567 - Mertens function zero
* 2568 - Mertens function zero. Also number of digits in the decimal expansion of 1000!, or the product of all natural numbers from 1 to 1000.
* 2570 - Mertens function zero
* 2579 - safe prime
* 2580 - Keith number
* 2584 - Fibonacci number, sum of the first 37 primes
* 2596 - sum of the totient function for the first 92 integers
* 2600 - tetrahedral number, member of a Ruth-Aaron pair with 2601 (first definition)
** 2600 Hz is the tone used by a blue box to defeat toll charges on long distance telephone calls.
** is a magazine named after the above.
** The Atari 2600 was a popular video game console.
* 2601 - $51^2$, member of a Ruth-Aaron pair with 2600 (first definition)
* 2620 - amicable number with 2924
* 2626 - decagonal number
* 2628 - triangular number
* 2632 - number of consecutive baseball games played by Cal Ripken, Jr.
* 2641 - centered pentagonal number
* 2647 - centered heptagonal number
* 2652 - pronic number
* 2656 - sum of the totient function for the first 93 integers
* 2674 - nonagonal number
* 2677 - balanced prime
* 2680 - number of 11-Queens Problem solutions
* 2689 - Mertens function zero, Proth prime
* 2693 - Sophie Germain prime
* 2699 - Sophie Germain prime
* 2701 - triangular number, super-Poulet number
* 2702 - sum of the totient function for the first 94 integers
* 2704 - $52^2$
* 2728 - Kaprekar number
* 2729 - highly cototient number
* 2731 - Wagstaff prime
* 2736 - octahedral number
* 2741 - Sophie Germain prime
* 2744 - $14^3$
* 2747 - sum of the first 38 primes
* 2753 - Sophie Germain prime, Proth prime
* 2756 - pronic number
* 2774 - sum of the totient function for the first 95 integers
* 2775 - triangular number
* 2780 - member of the Mian-Chowla sequence
* 2783 - member of a Ruth-Aaron pair with 2784 (first definition)
* 2784 - member of a Ruth-Aaron pair with 2783 (first definition)
* 2791 - cuban prime
* 2806 - centered pentagonal number, sum of the totient function for the first 96 integers
* 2809 - $53^2$, centered octagonal number
* 2819 - Sophie Germain prime, safe prime
* 2821 - Carmichael number
* 2835 - odd abundant number, decagonal number
* 2843 - centered heptagonal number
* 2850 - triangular number
* 2862 - pronic number
* 2870 - square pyramidal number
* 2871 - nonagonal number
* 2872 - tetranacci number
* 2879 - safe prime
* 2897 - Markov number
* 2902 - sum of the totient function for the first 97 integers
* 2903 - Sophie Germain prime, safe prime, balanced prime
* 2914 - sum of the first 39 primes
* 2915 - Lucas-Carmichael number
* 2916 - $54^2$
* 2924 - amicable number with 2620
* 2925 - magic constant of "n"×"n" normal magic square and "n"-Queens Problem for "n" = 18, tetrahedral number, member of the Mian-Chowla sequence
* 2926 - triangular number
* 2939 - Sophie Germain prime
* 2944 - sum of the totient function for the first 98 integers
* 2963 - Sophie Germain prime, safe prime, balanced prime
* 2965 - greater of 2nd pair of Smith brothers
* 2969 - Sophie Germain prime
* 2970 - harmonic divisor number, pronic number
* 2976 - centered pentagonal number
* 2997 - chiliagonal number
* 2999 - safe prime