Divisor 12003

To determine if any number is divisible by 12003, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 3 and 4001 - then it is divisible by 12003.

The following tests must pass:

• Test if a number is divisible by 3
• The "Jacob Melcher Test" for Divisibility by 4001

Easy!