Four hundred five
405 is an odd number.
405 is a Harshad number, which means it is divisible by the sum of its digits (4 + 0 + 5 = 9, and 405 is divisible by 9).
In binary, 405 is represented as 110010101.
In hex, 405 is represented as 195.
Prime factorization of 405: 34 * 5.