Divisor 6367

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

The "Porus Test" for Divisibility by 6367

To determine if any number is divisible by 6367, apply the "Porus Test":

  1. If your number ("X") has 9 digits or more, separate the last (smallest) 8 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 9 digits, L = 0 and therefore R = X.
  2. Multiply L by 102 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 1910 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 6367. That is, your original number is divisible by 6367 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 6367-times tables, it should be easy to visually see if Y is divisible by 6367. If the Y is still much larger than 6367, the above process can be repeated until it does reduce to within small multiples of 6367.

Easy!