Divisor 15527

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

The "Matthew Schuster Test" for Divisibility by 15527

To determine if any number is divisible by 15527, apply the "Matthew Schuster Test":

  1. If your number ("X") has 8 digits or more, separate the last (smallest) 7 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 8 digits, L = 0 and therefore R = X.
  2. Multiply L by 612 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 4658 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 15527. That is, your original number is divisible by 15527 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 15527-times tables, it should be easy to visually see if Y is divisible by 15527. If the Y is still much larger than 15527, the above process can be repeated until it does reduce to within small multiples of 15527.

Easy!