Fatto generale: 8320 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 8320 is the number of subsets of {1, 1/2, 1/3, ... 1/42} that sum to an integer.
Trivia: 8320 is an unremarkable number.
Data storica: October 11th is the day in 1634 that the Burchardi flood – "the second Grote Mandrenke" killed around 15,000 men in North Friesland, Denmark and Germany.