Divisor 10711

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

The "Thomas Leese Test" for Divisibility by 10711

To determine if any number is divisible by 10711, apply the "Thomas Leese 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 382 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 1071 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 10711. That is, your original number is divisible by 10711 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 10711-times tables, it should be easy to visually see if Y is divisible by 10711. If the Y is still much larger than 10711, the above process can be repeated until it does reduce to within small multiples of 10711.

Easy!