Divisor 4973

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

The "Blake Carlson Test" for Divisibility by 4973

To determine if any number is divisible by 4973, apply the "Blake Carlson 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 54 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 1492 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 4973. That is, your original number is divisible by 4973 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 4973-times tables, it should be easy to visually see if Y is divisible by 4973. If the Y is still much larger than 4973, the above process can be repeated until it does reduce to within small multiples of 4973.

Easy!