Divisor 15187

To determine if any number is divisible by 15187, apply the "mykr0pht Test":

1. If your number ("X") has 11 digits or more, separate the last (smallest) 10 digits from the rest. This makes two smaller numbers, call them L^eft and R^ight (note: don't add in trailing zeros to L). If there are fewer than 11 digits, L = 0 and therefore R = X.
2. Multiply L by 1646 and subtract this from R.
3. Take that result and cross off its final digit (units). Take this new number and subtract 4556 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 15187. That is, your original number is divisible by 15187 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 15187-times tables, it should be easy to visually see if Y is divisible by 15187. If the Y is still much larger than 15187, the above process can be repeated until it does reduce to within small multiples of 15187.

Easy!