Divisor 15821

To determine if any number is divisible by 15821, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 13 and 1217 - then it is divisible by 15821.

The following tests must pass:

• Test if a number is divisible by 13
• The "Capel Hanbury-Tenison Test" for Divisibility by 1217

Easy!