Divisor 21381

To determine if any number is divisible by 21381, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 3 and 7127 - then it is divisible by 21381.

The following tests must pass:

• Test if a number is divisible by 3
• The "M Test" for Divisibility by 7127

Easy!