Divisor 18989

To determine if any number is divisible by 18989, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 17 and 1117 - then it is divisible by 18989.

The following tests must pass:

• Test if a number is divisible by 17
• The "Russell Test" for Divisibility by 1117

Easy!