Divisor 20761

To determine if any number is divisible by 20761, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 13 and 1597 - then it is divisible by 20761.

The following tests must pass:

• Test if a number is divisible by 13
• The "Jonathan O'Sullivan Test" for Divisibility by 1597

Easy!