Divisor 19771

To determine if any number is divisible by 19771, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 17 and 1163 - then it is divisible by 19771.

The following tests must pass:

• Test if a number is divisible by 17
• The "Michal Kobelka Test" for Divisibility by 1163

Easy!