Fait général: 4890 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 4890 is a narcissistic number in base 5.
Culture générale: 4890 is an unremarkable number.
Date historique: 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.