Divisor 21161

To determine if any number is divisible by 21161, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 7 and 3023 - then it is divisible by 21161.

The following tests must pass:

• Test if a number is divisible by 7
• The "David Pekrul Test" for Divisibility by 3023

Easy!