General fact: 4485 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 4485 is the number of 3×3 sliding puzzle positions that require exactly 16 moves to solve starting with the hole in a corner.
Trivia: 4485 is an unremarkable number.
Historical date: April 11th is the day in 2001 that the detained crew of a United States EP-3E aircraft that landed in Hainan, China after a collision with a J-8 fighter is released.