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

4001 to 4099

* 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
* 4027 – super-prime
* 4028 – sum of the first 45 primes
* 4030 – third weird number
* 4031 – sum of the cubes of the first six primes
* 4032 – pronic number
* 4033 – sixth super-Poulet number; strong pseudoprime in base 2
* 4060 – tetrahedral number
* 4073 – Sophie Germain prime
* 4079 – safe prime
* 4091 – super-prime
* 4092 – an occasional glitch in the game The Legend of Zelda: Ocarina of Time causes the Gossip Stones to say this number
* 4095 – triangular number and odd abundant number; number of divisors in the sum of the fifth and largest known unitary perfect number, largest Ramanujan–Nagell number of the form $2^ - 1$.
* 4096 = 64² = 16³ = 8⁴ = 4⁶ = 2¹², the smallest number with exactly 13 divisors, a superperfect number

4100 to 4199

* 4104 = 2³ + 16³ = 9³ + 15³
* 4127 – safe prime
* 4133 – super-prime
* 4139 – safe prime
* 4140 – Bell number
* 4141 – centered square number
* 4147 – smallest cyclic number in duodecimal represented in base-12 notation as 2497₁₂.
2×4147_dez = 4972₁₂
3×4147_dez = 7249₁₂
4×4147_dez = 9724₁₂
* 4153 – super-prime
* 4160 – pronic number
* 4166 – centered heptagonal number,
* 4167 = 7! − 6! − 5! − 4! − 3! − 2! − 1!, number of planar partitions of 14
* 4169 – a number of points of norm n Fibonacci number