Divisor 12431

To determine if any number is divisible by 12431, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 31 and 401 - then it is divisible by 12431.

The following tests must pass:

• Test if a number is divisible by 31
• Test if a number is divisible by 401

Easy!