Divisor 20513

To determine if any number is divisible by 20513, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 73 and 281 - then it is divisible by 20513.

The following tests must pass:

• Test if a number is divisible by 73
• Test if a number is divisible by 281

Easy!