Divisor 1847

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

The "Scott Panton Test" for Divisibility by 1847

To determine if any number is divisible by 1847, apply the "Scott Panton Test":

  1. If your number ("X") has 6 digits or more, separate the last (smallest) 5 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 6 digits, L = 0 and therefore R = X.
  2. Multiply L by 262 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 554 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 1847. That is, your original number is divisible by 1847 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 1847-times tables, it should be easy to visually see if Y is divisible by 1847. If the Y is still much larger than 1847, the above process can be repeated until it does reduce to within small multiples of 1847.

Easy!