595

595 = 5 x 7 x 17.

595 is the 34th triangular number (the sum of the first 34 integers).

595 is a centered nonagonal number.

595 is the number of ways to tile a 3 x 18 rectangle with 3 x 1 rectangles.

595 is 151 in base 22.

Source: Whar's Special About This Number?