3900

3900 = 2 x 2 x 3 x 5 x 5 x 13.

3900 has a base 2 representation (111100111100) that is two copies of its base 5 representation (111100) concatenated (A175514). It is 330330 in base 4 (A045075) and 7474 in base 8 (A033079). It is 14241 in base 7 (palindromic).

3900 is the number of rooted trees with 15 nodes and 4 leaves (A055279).

3900 is the sum of four distinct powers of 5 (A038476).

3900 divides 49⁶ - 1.

Source: What's Special About This Number?