Divisor 5897

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

The "william barnard Test" for Divisibility by 5897

To determine if any number is divisible by 5897, apply the "william barnard Test":

  1. If your number ("X") has 6 digits or more, separate the last (smallest) 5 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 6 digits, L = 0 and therefore R = X.
  2. Multiply L by 249 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 1769 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 5897. That is, your original number is divisible by 5897 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 5897-times tables, it should be easy to visually see if Y is divisible by 5897. If the Y is still much larger than 5897, the above process can be repeated until it does reduce to within small multiples of 5897.

Easy!