Divisor 25989

To determine if any number is divisible by 25989, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 3 and 8663 - then it is divisible by 25989.

The following tests must pass:

• Test if a number is divisible by 3
• The "Derek Elliott Test" for Divisibility by 8663

Easy!