Divisor 3881

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

The "Hans Timmers Test" for Divisibility by 3881

To determine if any number is divisible by 3881, apply the "Hans Timmers 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 906 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 388 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 3881. That is, your original number is divisible by 3881 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 3881-times tables, it should be easy to visually see if Y is divisible by 3881. If the Y is still much larger than 3881, the above process can be repeated until it does reduce to within small multiples of 3881.

Easy!