Divisor 19521

To determine if any number is divisible by 19521, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 81 and 241 - then it is divisible by 19521.

The following tests must pass:

• Test if a number is divisible by 81
• Test if a number is divisible by 241

Easy!