Divisor 10939

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

The "Jammu Test" for Divisibility by 10939

To determine if any number is divisible by 10939, apply the "Jammu 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 376 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 1094 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 10939. That is, your original number is divisible by 10939 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 10939-times tables, it should be easy to visually see if Y is divisible by 10939. If the Y is still much larger than 10939, the above process can be repeated until it does reduce to within small multiples of 10939.

Easy!