Divisor 11833

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

The "drimtajm Test" for Divisibility by 11833

To determine if any number is divisible by 11833, apply the "drimtajm 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 683 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 3550 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 11833. That is, your original number is divisible by 11833 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 11833-times tables, it should be easy to visually see if Y is divisible by 11833. If the Y is still much larger than 11833, the above process can be repeated until it does reduce to within small multiples of 11833.

Easy!