Fatto generale: 524 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 524 is the number of 6-kings.
Trivia: 524 is an unremarkable number.
Data storica: June 7th is the day in 1989 that Surinam Airways Flight 764 crashes on approach to Paramaribo-Zanderij International Airport in Suriname due to pilot error, killing 176 of 187 aboard.