Divisor 10627

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

The "Rīki Test" for Divisibility by 10627

To determine if any number is divisible by 10627, apply the "Rīki 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 7 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 3188 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 10627. That is, your original number is divisible by 10627 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 10627-times tables, it should be easy to visually see if Y is divisible by 10627. If the Y is still much larger than 10627, the above process can be repeated until it does reduce to within small multiples of 10627.

Easy!