Divisor 25933

Prime Number:
Yes!
Divisibility test:
The "micky2be Test"
Test Discovered by:
Matt Parker
Date:
11/11/2024

The "micky2be Test" for Divisibility by 25933

To determine if any number is divisible by 25933, apply the "micky2be 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 1803 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 7780 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 25933. That is, your original number is divisible by 25933 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 25933-times tables, it should be easy to visually see if Y is divisible by 25933. If the Y is still much larger than 25933, the above process can be repeated until it does reduce to within small multiples of 25933.

Easy!