Divisor 10061

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

The "Nathan Brown Test" for Divisibility by 10061

To determine if any number is divisible by 10061, apply the "Nathan Brown 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 157 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 1006 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 10061. That is, your original number is divisible by 10061 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 10061-times tables, it should be easy to visually see if Y is divisible by 10061. If the Y is still much larger than 10061, the above process can be repeated until it does reduce to within small multiples of 10061.

Easy!