Divisor 23539

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

The "Daniel Buza Test" for Divisibility by 23539

To determine if any number is divisible by 23539, apply the "Daniel Buza 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 2753 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 2354 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 23539. That is, your original number is divisible by 23539 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 23539-times tables, it should be easy to visually see if Y is divisible by 23539. If the Y is still much larger than 23539, the above process can be repeated until it does reduce to within small multiples of 23539.

Easy!