453

453 = 3 x 151.

453 is the only number n such that n, 2n, and 6n together contain every digit exactly once: 453, 906, and 2718.

453 is 381 in base 11 and 318 in base 12. It is 202 in base 15.

453 is the sum of distinct double factorials: 453 = 8!! + 6!! + 5!! + 3!! + 2!! + 1!!

Source: What's Special About This Number?