Divisor 8991

To determine if any number is divisible by 8991, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 243 and 37 - then it is divisible by 8991.

The following tests must pass:

• Test if a number is divisible by 243
• Test if a number is divisible by 37

Easy!