Divisor 20015

To determine if any number is divisible by 20015, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 5 and 4003 - then it is divisible by 20015.

The following tests must pass:

• Test if a number is divisible by 5
• The "Filip Sowa Test" for Divisibility by 4003

Easy!