True story. About 10 years ago when I was working at the Stanford Linear Accelerator Center (
SLAC) -- a high-energy research lab that looks into the subatomic structure of matter -- a coworker realized that an office phone number of the first decimal digits of pi was not in use and available as an extension within the SLAC telephone exchange (415.926.5xxx): +1.415.926.5358 (i.e., drop the initial "3"...).
Why not one single physicist or mathematician there ever recognized that or thought of asking for it was actually kind of dumbfounding. It turned out that it was the only place in all the world that it was possible.
But a couple years later the local telephone exchange split up the 415 area code (to accommodate more mobile phones, etc.) so that San Francisco retained the "415" area code and the peninsula, where SLAC is, got "650" instead. That pretty much put an end to that.