Divisor 9629

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

The "clive jackson Test" for Divisibility by 9629

To determine if any number is divisible by 9629, apply the "clive jackson Test":

  1. If your number ("X") has 5 digits or more, separate the last (smallest) 4 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 5 digits, L = 0 and therefore R = X.
  2. Multiply L by 371 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 963 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 9629. That is, your original number is divisible by 9629 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 9629-times tables, it should be easy to visually see if Y is divisible by 9629. If the Y is still much larger than 9629, the above process can be repeated until it does reduce to within small multiples of 9629.

Easy!