Divisor 15053

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

The "Andrew Carr Test" for Divisibility by 15053

To determine if any number is divisible by 15053, apply the "Andrew Carr Test":

  1. If your number ("X") has 10 digits or more, separate the last (smallest) 9 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 10 digits, L = 0 and therefore R = X.
  2. Multiply L by 896 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 4516 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 15053. That is, your original number is divisible by 15053 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 15053-times tables, it should be easy to visually see if Y is divisible by 15053. If the Y is still much larger than 15053, the above process can be repeated until it does reduce to within small multiples of 15053.

Easy!