Divisor 11633

Prime Number:
Yes!
Divisibility test:
The "Dr. Jacob Oost Test"
Test Discovered by:
Matt Parker
Date:
11/11/2024

The "Dr. Jacob Oost Test" for Divisibility by 11633

To determine if any number is divisible by 11633, apply the "Dr. Jacob Oost Test":

  1. If your number ("X") has 7 digits or more, separate the last (smallest) 6 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 7 digits, L = 0 and therefore R = X.
  2. Multiply L by 438 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 3490 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 11633. That is, your original number is divisible by 11633 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 11633-times tables, it should be easy to visually see if Y is divisible by 11633. If the Y is still much larger than 11633, the above process can be repeated until it does reduce to within small multiples of 11633.

Easy!