Divisor 20531

To determine if any number is divisible by 20531, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 49 and 419 - then it is divisible by 20531.

The following tests must pass:

• Test if a number is divisible by 49
• Test if a number is divisible by 419

Easy!