Fait mathématique: 9135 is a value of n for which 2n and 7n together use each digit exactly once.
Culture générale: 9135 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: January 3rd is the day in 1996 that the Motorola StarTAC, the first flip phone and one of the first mobile phones to gain widespread consumer adoption, goes on sale.