Divisor 19087

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

The "Technology Connections Test" for Divisibility by 19087

To determine if any number is divisible by 19087, apply the "Technology Connections 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 1588 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 5726 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 19087. That is, your original number is divisible by 19087 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 19087-times tables, it should be easy to visually see if Y is divisible by 19087. If the Y is still much larger than 19087, the above process can be repeated until it does reduce to within small multiples of 19087.

Easy!