3000

3000 = 2³ x 3 x 5³.

3000 is MMM, the largest palindrome in Roman numerals.

3000 is 101110111000 in base 2, 232320 in base 4, 44000 in base 5, 2288 in base 11, 1144 in base 14, and 550 in base 24.

3000 is the number of symmetric arrangements of seven non-attacking queens on a 7 x 7 chessboard.

3000 is the smallest number requiring more than 12 letters to write in the English language. Three thousand uses 13 letters.

Source: Number Gossip