Divisor 20323

Prime Number:
Yes!
Divisibility test:
The "F. Murmel Test"
Test Discovered by:
Matt Parker
Date:
11/11/2024

The "F. Murmel Test" for Divisibility by 20323

To determine if any number is divisible by 20323, apply the "F. Murmel 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 1084 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 6097 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 20323. That is, your original number is divisible by 20323 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 20323-times tables, it should be easy to visually see if Y is divisible by 20323. If the Y is still much larger than 20323, the above process can be repeated until it does reduce to within small multiples of 20323.

Easy!