Divisor 25313

To determine if any number is divisible by 25313, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 17 and 1489 - then it is divisible by 25313.

The following tests must pass:

• Test if a number is divisible by 17
• The "Christopher Test" for Divisibility by 1489

Easy!