Fatto generale: 4590 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 4590 is an unremarkable number.
Trivia: 4590 is an uninteresting number.
Data storica: July 25th is the day in 1792 that the Brunswick Manifesto is issued to the population of Paris promising vengeance if the French Royal Family is harmed.