Divisor 22937

Prime Number:
Yes!
Divisibility test:
The "Simon Allen Test"
Test Discovered by:
Matt Parker
Date:
11/11/2024

The "Simon Allen Test" for Divisibility by 22937

To determine if any number is divisible by 22937, apply the "Simon Allen Test":

  1. If your number ("X") has 8 digits or more, separate the last (smallest) 7 digits from the rest. This makes two smaller numbers, call them Left and Right (note: don't add in trailing zeros to L). If there are fewer than 8 digits, L = 0 and therefore R = X.
  2. Multiply L by 532 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 6881 times the digit you just crossed off. Call this final result "Y".
  4. Y will be much smaller than X, but we have preserved divisibility by 22937. That is, your original number is divisible by 22937 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 22937-times tables, it should be easy to visually see if Y is divisible by 22937. If the Y is still much larger than 22937, the above process can be repeated until it does reduce to within small multiples of 22937.

Easy!