Divisor 4457

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

The "Amit Bueno Test" for Divisibility by 4457

To determine if any number is divisible by 4457, apply the "Amit Bueno Test":

  1. If your number ("X") has 10 digits or more, separate the last (smallest) 9 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 10 digits, L = 0 and therefore R = X.
  2. Multiply L by 738 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 1337 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 4457. That is, your original number is divisible by 4457 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 4457-times tables, it should be easy to visually see if Y is divisible by 4457. If the Y is still much larger than 4457, the above process can be repeated until it does reduce to within small multiples of 4457.

Easy!