Divisor 14879

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

The "gropius Test" for Divisibility by 14879

To determine if any number is divisible by 14879, apply the "gropius 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 1312 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 1488 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 14879. That is, your original number is divisible by 14879 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 14879-times tables, it should be easy to visually see if Y is divisible by 14879. If the Y is still much larger than 14879, the above process can be repeated until it does reduce to within small multiples of 14879.

Easy!