Divisor 11159

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

The "Matt Dunford Test" for Divisibility by 11159

To determine if any number is divisible by 11159, apply the "Matt Dunford Test":

  1. If your number ("X") has 6 digits or more, separate the last (smallest) 5 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 6 digits, L = 0 and therefore R = X.
  2. Multiply L by 431 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 1116 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 11159. That is, your original number is divisible by 11159 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 11159-times tables, it should be easy to visually see if Y is divisible by 11159. If the Y is still much larger than 11159, the above process can be repeated until it does reduce to within small multiples of 11159.

Easy!