Divisor 9533

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

The "Fabian Enkler Test" for Divisibility by 9533

To determine if any number is divisible by 9533, apply the "Fabian Enkler 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 117 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 2860 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 9533. That is, your original number is divisible by 9533 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 9533-times tables, it should be easy to visually see if Y is divisible by 9533. If the Y is still much larger than 9533, the above process can be repeated until it does reduce to within small multiples of 9533.

Easy!