Divisor 6401

To determine if any number is divisible by 6401, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 37 and 173 - then it is divisible by 6401.

The following tests must pass:

• Test if a number is divisible by 37
• Test if a number is divisible by 173

Easy!