Divisor 18041

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

The "Xuan Li Leong Test" for Divisibility by 18041

To determine if any number is divisible by 18041, apply the "Xuan Li Leong 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 13 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 1804 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 18041. That is, your original number is divisible by 18041 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 18041-times tables, it should be easy to visually see if Y is divisible by 18041. If the Y is still much larger than 18041, the above process can be repeated until it does reduce to within small multiples of 18041.

Easy!