3500

3500 = 2 x 2 x 5 x 5 x 5 x 7.

3500 is a number that is the sum of two positive cubes and divisible by 7 (A101421) and divisible by 5 (A224485).

3500 is the sum of three nonnegative cubes in more than one way (A001239).

3500 is the number of rooted trees with 24 nodes with every leaf at height 3 (A048808).

3500 is a number n such that n and the square of n have only the digits 0, 1, 2, 3, and 5 in common (A136811).

3500 divides 57⁴ - 1.

Source: OEIS