Divisor 5903

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

The "Nancy Flores Test" for Divisibility by 5903

To determine if any number is divisible by 5903, apply the "Nancy Flores 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 318 and add to R.
  3. Take that result and cross off its final digit (units). Take this new number and add 1771 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 5903. That is, your original number is divisible by 5903 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 5903-times tables, it should be easy to visually see if Y is divisible by 5903. If the Y is still much larger than 5903, the above process can be repeated until it does reduce to within small multiples of 5903.

Easy!