The Small Vampire Numbers

Here are the seven four-digit vampire numbers:

1) 15 x 93 = 1,395
2) 21 x 60 = 1,260
3) 21 x 87 = 1,827
4) 27 x 81 = 2,187
5) 30 x 51 = 1,530
6) 35 x 41 = 1,435
7) 80 x 86 = 6,880

There are 4,095 possible two-digit x two-digit non-duplicate possible multiplications. Since only 7 are vampire results, we find that only 0.2% of the possible numbers are vampires.

Since there are only 148 (true) six-digit vampire numbers, and 405,450 possibilities, only 0.04% are vampires! The percentage shrinks, but there are a LOT of big numbers out there!

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