Divisor 2027

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

The "PartyPirate Test" for Divisibility by 2027

To determine if any number is divisible by 2027, apply the "PartyPirate 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 18 and subtract this from R.
  3. Take that result and cross off its final digit (units). Take this new number and subtract 608 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 2027. That is, your original number is divisible by 2027 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 2027-times tables, it should be easy to visually see if Y is divisible by 2027. If the Y is still much larger than 2027, the above process can be repeated until it does reduce to within small multiples of 2027.

Easy!