-3 is an odd number.
-3 is a Harshad number, which means it is divisible by the sum of its digits (3 = 3, and -3 is divisible by 3).
In binary, -3 is represented as 1111111111111111111111111111111111111111111111111111111111111101.
In hex, -3 is represented as fffffffffffffffd.