Divisor 21729

To determine if any number is divisible by 21729, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 3 and 7243 - then it is divisible by 21729.

The following tests must pass:

• Test if a number is divisible by 3
• The "Laretta & Mindolo Test" for Divisibility by 7243

Easy!