Divisor 20557

To determine if any number is divisible by 20557, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 61 and 337 - then it is divisible by 20557.

The following tests must pass:

• Test if a number is divisible by 61
• Test if a number is divisible by 337

Easy!