general_fact: 21089 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 21089 is an unremarkable number.
trivia: 21089 is a boring number.
historical_date: September 26th is the day in 1997 that an earthquake strikes the Italian regions of Umbria and the Marche, causing part of the Basilica of St. Francis at Assisi to collapse.