Divisor 6047

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

The "Alan Rosenwinkel Test" for Divisibility by 6047

To determine if any number is divisible by 6047, apply the "Alan Rosenwinkel Test":

  1. If your number ("X") has 9 digits or more, separate the last (smallest) 8 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 9 digits, L = 0 and therefore R = X.
  2. Multiply L by 761 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 1814 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 6047. That is, your original number is divisible by 6047 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 6047-times tables, it should be easy to visually see if Y is divisible by 6047. If the Y is still much larger than 6047, the above process can be repeated until it does reduce to within small multiples of 6047.

Easy!