Fatto matematico: 1237 is the smallest prime that contains exactly 5 smaller primes as substrings.
Trivia: 1237 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: May 21st is the day in 1937 that a Soviet station, North Pole-1, becomes the first scientific research settlement to operate on the drift ice of the Arctic Ocean.