Fatto generale: 1524 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 1524 is an uninteresting number.
Trivia: 1524 is a boring number.
Data storica: March 3rd is the day in 2009 that the building of the Historisches Archiv der Stadt Köln (Historical Archives) in Cologne, Germany, collapses.