General fact: 4255 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 4255 is a centered tetrahedral number.
Trivia: 4255 is an unremarkable number.
Historical date: August 25th is the day in 1894 that Kitasato Shibasaburō discovers the infectious agent of the bubonic plague and publishes his findings in The Lancet.