Divisor 15193

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

The "Jordan Moelis Test" for Divisibility by 15193

To determine if any number is divisible by 15193, apply the "Jordan Moelis 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 326 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 4558 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 15193. That is, your original number is divisible by 15193 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 15193-times tables, it should be easy to visually see if Y is divisible by 15193. If the Y is still much larger than 15193, the above process can be repeated until it does reduce to within small multiples of 15193.

Easy!