Divisor 2371

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

The "Lee Peltz Test" for Divisibility by 2371

To determine if any number is divisible by 2371, apply the "Lee Peltz 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 73 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 237 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 2371. That is, your original number is divisible by 2371 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 2371-times tables, it should be easy to visually see if Y is divisible by 2371. If the Y is still much larger than 2371, the above process can be repeated until it does reduce to within small multiples of 2371.

Easy!