Fatto generale: 5904 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 5904 is a boring number.
Trivia: 5904 is a boring number.
Data storica: February 29th is the day in 1988 that South African archbishop Desmond Tutu is arrested along with 100 clergymen during a five-day anti-apartheid demonstration in Cape Town.