Fatto matematico: 1624 is the Stirling number of the first kind s(7,3).
Trivia: 1624 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: June 11th is the day in 1903 that Group of Serbian officers stormed royal palace and assassinated King Alexander Obrenović and his wife queen Draga.