general_fact: 21008 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 21008 is an uninteresting number.
trivia: 21008 is an unremarkable number.
historical_date: July 7th is the day in 1981 that U.S. President Ronald Reagan appoints Sandra Day O'Connor to become the first female member of the Supreme Court of the United States.