A number divisible by an even number must be an even number.
The sum of digits of a number divisible by 3 is a multiple of 3.
The sum of digits of a number divisible by 9 is a multiple of 9.
One digit of a number divisible by 5 must be 0 or 5.
A number divisible by 1 1. The sum of odd digits is equal to the sum of even digits.