Divisor 20891

To determine if any number is divisible by 20891, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 13 and 1607 - then it is divisible by 20891.

The following tests must pass:

• Test if a number is divisible by 13
• The "Christofer.jh Test" for Divisibility by 1607

Easy!