Divisor 2953

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

The "Tiago Skora Test" for Divisibility by 2953

To determine if any number is divisible by 2953, apply the "Tiago Skora Test":

  1. If your number ("X") has 9 digits or more, separate the last (smallest) 8 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 9 digits, L = 0 and therefore R = X.
  2. Multiply L by 392 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and add 886 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 2953. That is, your original number is divisible by 2953 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 2953-times tables, it should be easy to visually see if Y is divisible by 2953. If the Y is still much larger than 2953, the above process can be repeated until it does reduce to within small multiples of 2953.

Easy!