General fact: 4525 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 4525 is an unremarkable number.
Trivia: 4525 is a boring number.
Historical date: May 21st is the day in 1936 that Sada Abe is arrested after wandering the streets of Tokyo for days with her dead lover's severed genitals in her hand.