1100 = 22 x 52 x 11.
1100 has a base 2 (binary) representation that ends in the digits 1100: 10001001100. 1100 is 3131 in base 7. It is 778 in base 12, 668 in base 13, and 588 in base 14.
1100 is the sum of a square and a cube: 1100 = 103 + 102. It is the sum of two distinct powers of 10.
1100 is the sum of eight positive fifth powers: 1100 = 35 + 35 + 35 + 35 + 25 + 25 + 25 + 25.
Source: Prime Curios!