Divisor 21057

To determine if any number is divisible by 21057, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 3 and 7019 - then it is divisible by 21057.

The following tests must pass:

• Test if a number is divisible by 3
• The "Christopher L Baker Test" for Divisibility by 7019

Easy!