general_fact: 542 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 542 is a member of the Fibonacci-type sequence starting with 3 and 8.
trivia: 542 is a boring number.
historical_date: June 25th is the day in 1906 that Pittsburgh, Pennsylvania millionaire Harry Thaw shoots and kills prominent architect Stanford White.