What Special About This Number

0-1000
0 is the additive identity.

1 is the Multiplicative Identity.

2 is the only even number is prime.

3 is the smallest k such that it is impossible to construction of an angle equal to 1/k of a given arbitrary angle using only an unmarked straightedge and a compass.

4 is the smallest number of colors sufficient to color all planar maps.

5 is the number of Platonic solids.

6 is the smallest perfect number.

7  is the smallest number of sides of a regular polygon that is not constructible by straightedge and compass.

8 is the largest cube in the Fibonacci sequence.

9 is the maximum number of cubes that are needed to sum to any positive integer

X is the smallest noncototient number.

B is the largest number which cannot be written as sum of two composite numbers.

J is the smallest abundant number.

10 is the base of our number system.

11 is the smallest nontotient number.

12 is the smallest k>1 such that the number of terms of the k-th cyclotomic polynomial does not equal to the largest prime factor of k.

13 is the only number of the form ab = ba (commutative powers), with a, b nonnegative integers, a ≠ b.

14 is the number of wallpaper groups.

15 is the only positive number that is twice the sum of its digits.

16 is the maximum number of 4th powers needed to sum to any number.

17 is the number of rooted trees with 6 vertices

18 is the smallest number of distinct squares needed to tile a square.

19 is the number of partitions of 8.

1X is the smallest number of integer-sided boxes that tile a box so that no two boxes share a common length.

1B is the largest number divisible by all numbers less than its square root.

1J is the smallest square that can be written as a sum of 2 positive squares.

20 is the only positive number to be directly between a square and a cube.

21 is the largest number that is the sum of the digits of its cube.

22 is conjectured to be the only number which can be expressed as a sum of the first positive integers (1 + 2 + 3 + 4 + 5 + 6 + 7), a sum of the first primes (2 + 3 + 5 + 7 + B) and a sum of the first nonprimes (1 + 4 + 6 + 8 + 9).

23 is the 7th Lucas number.

24 is the largest number with the property that all smaller numbers relatively prime to it are prime.

25 is a Mersenne prime.

26 is the smallest non-trivial 5th power.

27 is the largest number that is not a sum of distinct triangular numbers

28 is the smallest number with the property that it and its neighbors have the same number of divisors.

29 is the number of hexominoes

2X is the smallest perfect power which is not prime power.

2B is the smallest irregular prime.

2J is the magic constant of the only non-trivial normal magic hexagon.

30 is the smallest number which has 3 different partitions into 3 parts with the same product.

40 is the 5th Bell number.

48 is the smallest possible order of nonsolvable group.

52 is the sum of the last digit of the prime numbers below 30

279 is the number of 6-octs.

5J8 is the pseudosquare modulo 7.

1000 = 103