Divisor 16333

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

The "Brian Weiss Test" for Divisibility by 16333

To determine if any number is divisible by 16333, apply the "Brian Weiss 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 2002 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 4900 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 16333. That is, your original number is divisible by 16333 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 16333-times tables, it should be easy to visually see if Y is divisible by 16333. If the Y is still much larger than 16333, the above process can be repeated until it does reduce to within small multiples of 16333.

Easy!