Divisor 25153

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

The "Maxwell Lenko Test" for Divisibility by 25153

To determine if any number is divisible by 25153, apply the "Maxwell Lenko Test":

  1. If your number ("X") has 6 digits or more, separate the last (smallest) 5 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 6 digits, L = 0 and therefore R = X.
  2. Multiply L by 612 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 7546 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 25153. That is, your original number is divisible by 25153 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 25153-times tables, it should be easy to visually see if Y is divisible by 25153. If the Y is still much larger than 25153, the above process can be repeated until it does reduce to within small multiples of 25153.

Easy!