Mathematical fact: 22161 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 22161 is an unremarkable number.
Historical date: September 2nd is the day in 1963 that CBS Evening News becomes U.S. network television's first half-hour weeknight news broadcast, when the show is lengthened from 15 to 30 minutes.