Divisor 19679

To determine if any number is divisible by 19679, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 11 and 1789 - then it is divisible by 19679.

The following tests must pass:

• Test if a number is divisible by 11
• The "Otto Stephan Test" for Divisibility by 1789

Easy!