general_fact: 497 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 497 is the number of graphs with 8 edges.
trivia: 497 is an unremarkable number.
historical_date: May 11th is the day in 1968 that the Toronto Transit Commission opens the largest expansion of its Bloor–Danforth line, going to Scarborough in the East, and Etobicoke in the West.