Divisor 11959

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

The "Jeremy Dillman Test" for Divisibility by 11959

To determine if any number is divisible by 11959, apply the "Jeremy Dillman Test":

  1. If your number ("X") has 10 digits or more, separate the last (smallest) 9 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 10 digits, L = 0 and therefore R = X.
  2. Multiply L by 379 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 1196 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 11959. That is, your original number is divisible by 11959 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 11959-times tables, it should be easy to visually see if Y is divisible by 11959. If the Y is still much larger than 11959, the above process can be repeated until it does reduce to within small multiples of 11959.

Easy!