Fait mathématique: 2485 is the number of planar partitions of 13.
Culture générale: 2485 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: October 20th is the day in 1961 that the Soviet Union performs the first armed test of a submarine-launched ballistic missile, launching an R-13 from a Golf class submarine.