Even if you miss the poetical beauty of mathematics, it can be fun to check the Online Encyclopedia of Integer Sequences. If you fail to remember the sequence your ATM card brought to you is 23731211 – check at OEIS and you will see that these are the first 8 digits of Euclid numbers. From a different perspective, if you ATM code is at OEIS, you may well find reason to change it asap.

Quanta Magazine interviewed Neil Sloane, who founded OEIS in 1964 and keep collecting sequences since.