Divisor 10271

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

The "Cody Hammack Test" for Divisibility by 10271

To determine if any number is divisible by 10271, apply the "Cody Hammack 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 335 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 1027 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 10271. That is, your original number is divisible by 10271 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 10271-times tables, it should be easy to visually see if Y is divisible by 10271. If the Y is still much larger than 10271, the above process can be repeated until it does reduce to within small multiples of 10271.

Easy!