Everyone knows that a number with its units digit equal to 0, 2, 4, 6 or 8 is evenly divisible by two. Here’s a handy way to figure out if a number is divisible by 3. If the sum of the digits of the number in question is evenly divisible by 3 then that number also is divisible by 3.

Example:

Is 64,332 evenly divisible by 3?
Sum the digits of the number: 6 + 4 + 3 + 3 + 2 = 18
The answer is 18 which is evenly divisible by 3, so 64,332 is evenly divisible by 3.

A nice quick way to find out if 3 is a factor of a number or not!