Divisor 11117

Prime Number:
Yes!
Divisibility test:
The "9ZIgncPr8X3DnLlq Test"
Test Discovered by:
Matt Parker
Date:
11/11/2024

The "9ZIgncPr8X3DnLlq Test" for Divisibility by 11117

To determine if any number is divisible by 11117, apply the "9ZIgncPr8X3DnLlq 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 53 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 3335 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 11117. That is, your original number is divisible by 11117 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 11117-times tables, it should be easy to visually see if Y is divisible by 11117. If the Y is still much larger than 11117, the above process can be repeated until it does reduce to within small multiples of 11117.

Easy!