So for a number to be divisible by 6, it must also be divisible by 2 and 3. Therefore, we need to check if a number is even and then check if the sum of the digits is divisible by 3.
For example, lets take a really long number: 536,485,926
This number ends in an even number - 6.
Now we need to add all the digits together: 5+3+6+4+8+5+9+2+6 = 48
48 is divisible by 3. 48/3 = 16
This number is dibisible by both 2 and 3, so it is therefore divisible by 6.
536,485,926/6 = 89,414,321
