Divisor 1809

To determine if any number is divisible by 1809, you must apply 2 tests successively. If all of them 'pass' - that is, if your number is divisible by 27 and 67 - then it is divisible by 1809.

The following tests must pass:

• Test if a number is divisible by 27
• Test if a number is divisible by 67

Easy!