math_fact: 12123 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 12123 is an unremarkable number.
historical_date: March 10th is the day in 1891 that Almon Strowger, an undertaker in Topeka, Kansas, patents the Strowger switch, a device which led to the automation of telephone circuit switching.