Divisor 6404

To determine if any number is divisible by 6404, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 4 and 1601 - then it is divisible by 6404.

The following tests must pass:

• Test if a number is divisible by 4
• The "Lucas Höhne Test" for Divisibility by 1601

Easy!