4000 (number)

4000 (four thousand) is the natural number following 3999 and preceding 4001. It is a decagonal number.

Selected numbers in the range 4001-4999

* 4005 - triangular number
* 4007 - safe prime
* 4010 - magic constant of "n"×"n" normal magic square and n-Queens Problem for "n" = 20.
* 4013 - balanced prime
* 4019 - Sophie Germain prime
* 4028 - sum of the first 45 primes
* 4030 - 3rd weird number
* 4031 - sum of the cubes of the first six primes
* 4033 - 6th super-Poulet number; strong pseudoprime in base 2
* 4060 - tetrahedral number
* 4073 - Sophie Germain prime
* 4079 - safe prime
* 4095 - triangular number, the largest one of the form $2^k\; -\; 1$
* 4096 - power of two $2^\{12\}$; $64^2$; 16th cube; smallest number with exactly 13 divisors; a superperfect number
* 4104 - $2^3\; +\; 16^3\; =\; 9^3\; +\; 15^3$ (taxicab number)
* 4127 - safe prime
* 4139 - safe prime
* 4140 - Bell number
* 4166 - centered heptagonal number, 7!-6!-5!-4!-3!-2!-1!-0!
* 4167 - 7!-6!-5!-4!-3!-2!-1!
* 4168 - 7!-6!-5!-4!-3!-2!
* 4170 - 7!-6!-5!-4!-3!
* 4176 - 7!-6!-5!-4!
* 4181 - Fibonacci number, Markov number
* 4186 - triangular number
* 4187 - factor of R₁₃. Also record number of wickets taken in first-class cricket by Wilfred Rhodes.
* 4199 - highly cototient number
* 4200 - nonagonal number, pentagonal pyramidal number, 7!-6!-5!
* 4210 - 11th semi-meandric number
* 4211 - Sophie Germain prime
* 4219 - cuban prime of the form x = y + 1
* 4223 - Kynea number
* 4225 - $65^2$, centered octagonal number
* 4227 - sum of the first 46 primes
* 4240 - Leyland number
* 4257 - decagonal number
* 4259 - safe prime
* 4271 - Sophie Germain prime
* 4278 - triangular number
* 4283 - safe prime
* 4289 - highly cototient number
* 4320 - 7!-6!
* 4324 - 23rd square pyramidal number
* 4349 - Sophie Germain prime
* 4351 - 9 * 483.444...
* 4356 - $66^2$, sum of the cubes of the first eleven integers
* 4359 - perfect totient number
* 4369 - 7th super-Poulet number
* 4371 - triangular number
* 4373 - Sophie Germain prime
* 4375 - perfect totient number (the smallest not divisible by 3)
* 4391 - Sophie Germain prime
* 4397 - Year of Comet Hale-Bopp's return, a prime number
* 4400 - the number of missing persons in the sci-fi show "The 4400"
* 4409 - Sophie Germain prime, highly cototient number, balanced prime
* 4411 - centered heptagonal number
* 4421 - alternating factorial
* 4438 - sum of the first 47 primes
* 4446 - nonagonal number
* 4447 - cuban prime of the form x = y + 1
* 4457 - balanced prime
* 4465 - triangular number
* 4481 - Sophie Germain prime
* 4489 - $67^2$, centered octagonal number
* 4495 - tetrahedral number
* 4503 - largest number not the sum of four or fewer squares of composites
* 4505 - 5th Zeisel number
* 4522 - decagonal number
* 4547 - safe prime
* 4560 - triangular number
* 4579 - octahedral number
* 4597 - balanced prime
* 4607 - Woodall number
* 4619 - highly cototient number
* 4620 - the number appearing on all cheques in the Check Game (aka Blank Check) on the U.S. TV game show "The Price Is Right"
* 4624 - $68^2$
* 4641 - magic constant of "n"×"n" normal magic square and n-Queens Problem for "n" = 21.
* 4656 - triangular number
* 4657 - balanced prime
* 4661 - sum of the first 48 primes
* 4663 - centered heptagonal number
* 4679 - safe prime
* 4681 - 8th super-Poulet number
* 4691 - balanced prime
* 4699 - nonagonal number
* 4703 - safe prime
* 4705 - $48^2\; +\; 49^2\; =\; 17^2\; +\; 18^2\; +\; cdots\; +\; 26^2$
* 4727 - sum of the squares of the first twelve primes
* 4733 - Sophie Germain prime
* 4753 - triangular number
* 4761 - $69^2$, centered octagonal number
* 4787 - safe prime
* 4788 - 14th Keith number
* 4793 - Sophie Germain prime
* 4795 - decagonal number
* 4799 - safe prime
* 4801 - cuban prime of the form x = y + 2, smallest prime with a composite sum of digits in base 7
* 4851 - triangular number, pentagonal pyramidal number
* 4862 - Catalan number
* 4871 - Sophie Germain prime
* 4879 - 11th Kaprekar number
* 4888 - sum of the first 49 primes
* 4900 - $70^2$, the only square-pyramidal square other than 1 [http://mathworld.wolfram.com/CannonballProblem.html]
* 4913 - 17th cube
* 4919 - Sophie Germain prime, safe prime
* 4922 - centered heptagonal number
* 4941 - centered cube number
* 4943 - Sophie Germain prime
* 4950 - triangular number, 12th Kaprekar number
* 4959 - nonagonal number
* 4960 - tetrahedral number; greater of 4th pair of Smith brothers
* 4991 - Lucas-Carmichael number
* 4993 - balanced prime