Divisor 20621

To determine if any number is divisible by 20621, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 17 and 1213 - then it is divisible by 20621.

The following tests must pass:

• Test if a number is divisible by 17
• The "Eli Kaituri Test" for Divisibility by 1213

Easy!