My dad, a nuclear physicist, always had his briefcase locked with the combination 137-731. As a kid I just knew it was "some important physics number".

(He never kept anything super secret in there as far as I know; the lock was just to stop it from opening by accident)

That's funny, back when I worked at Bell Labs many years ago, back when we carried briefcases, mine was 314. I remember getting into an argument (friendly) with this guy when he noticed it and told me I should be using 137. We had a big long discussion about which number is more important or more meaningful, Pi, Fine Structure, Golden Ratio, Euler's, etc. It would be funny if it turned out there is some mathematical combination of those that is 42 !