Divisor 14939

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

The "Hannes Güdelhöfer Test" for Divisibility by 14939

To determine if any number is divisible by 14939, apply the "Hannes Güdelhöfer Test":

  1. If your number ("X") has 7 digits or more, separate the last (smallest) 6 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 7 digits, L = 0 and therefore R = X.
  2. Multiply L by 913 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 1494 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 14939. That is, your original number is divisible by 14939 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 14939-times tables, it should be easy to visually see if Y is divisible by 14939. If the Y is still much larger than 14939, the above process can be repeated until it does reduce to within small multiples of 14939.

Easy!