Fatto generale: 39 is the duration, in nanoseconds, of the nuclear reaction in the largest nuclear explosion ever performed (Tsar bomb).
Fatto matematico: 39 is the sum of five consecutive primes (3 + 5 + 7 + 11 + 13) and the sum of the first three powers of 3 (31 + 32 + 33).
Trivia: 39 is the number of mentions of work or labor in the Torah.
Data storica: February 8th is the day in 1601 that Robert Devereux, 2nd Earl of Essex, rebels against Queen Elizabeth I – the revolt is quickly crushed.