Explanation Divisibility Test for 6:
A number is divisible by 6 if it is divisible by 3 and 2 i.e. all even numbers that are divisible by 3 are divisible by 6 !
So to find if 367864 is divisible by 3 ( check if the sum of digits is divisible by 3) ,
3 + 6 + 7 + 8 + 6 + 6 =36 which is divisible by 3, Hence 367864 is divisible by 3.
Now that the number is even it has to be divisible by 2. So,
The number is also divisible by 6.