Divisor 1691

To determine if any number is divisible by 1691, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 19 and 89 - then it is divisible by 1691.

The following tests must pass:

• Test if a number is divisible by 19
• Test if a number is divisible by 89

Easy!