Divisor 24203

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

The "Pascal Gatzki Test" for Divisibility by 24203

To determine if any number is divisible by 24203, apply the "Pascal Gatzki Test":

  1. If your number ("X") has 11 digits or more, separate the last (smallest) 10 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 11 digits, L = 0 and therefore R = X.
  2. Multiply L by 1916 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 7261 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 24203. That is, your original number is divisible by 24203 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 24203-times tables, it should be easy to visually see if Y is divisible by 24203. If the Y is still much larger than 24203, the above process can be repeated until it does reduce to within small multiples of 24203.

Easy!