Divisor 20609

To determine if any number is divisible by 20609, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 37 and 557 - then it is divisible by 20609.

The following tests must pass:

• Test if a number is divisible by 37
• Test if a number is divisible by 557

Easy!