....when you are dividing by 3's, the way you can check to see that the number IS divisible by 3 is to add all the digits together, and that sum should be divisible by 3. The number before mine, which is 331,955 is adds this way:
3 + 3 + 1 + 9 + 5 + 5 = 26, which, of course, is NOT divisible by 3....