Divisor 15999

To determine if any number is divisible by 15999, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 3 and 5333 - then it is divisible by 15999.

The following tests must pass:

• Test if a number is divisible by 3
• The "Ray Johnston Test" for Divisibility by 5333

Easy!