Divisor 6829

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

The "Ben Clifford Test" for Divisibility by 6829

To determine if any number is divisible by 6829, apply the "Ben Clifford 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 2214 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 683 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 6829. That is, your original number is divisible by 6829 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 6829-times tables, it should be easy to visually see if Y is divisible by 6829. If the Y is still much larger than 6829, the above process can be repeated until it does reduce to within small multiples of 6829.

Easy!