Divisor 5653

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

The "Vijay Test" for Divisibility by 5653

To determine if any number is divisible by 5653, apply the "Vijay Test":

  1. If your number ("X") has 8 digits or more, separate the last (smallest) 7 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 8 digits, L = 0 and therefore R = X.
  2. Multiply L by 157 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 1696 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 5653. That is, your original number is divisible by 5653 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 5653-times tables, it should be easy to visually see if Y is divisible by 5653. If the Y is still much larger than 5653, the above process can be repeated until it does reduce to within small multiples of 5653.

Easy!