455

455 = 5 x 7 x 13.

455 is 111000111 in base 2 (binary), and it is 555 in base 9.

455 is the 13th tetrahedral number.

455 is a number that cannot be written as a sum of three squares.

455 is the number of plus signs needed to write the partitions of 13.

Kathy Mattea sang 455 Rocket, a song celebrating Oldsmobiles of the 1960s and 70s with the high-powered 455 Rocket V8 engine.

Source: Number Gossip