general_fact: 7351 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 7351 is a value of n for which n, 2n, 3n, and 4n all use the same number of digits in Roman numerals.
trivia: 7351 is an uninteresting number.
historical_date: February 15th is the day in 1965 that a new red-and-white maple leaf design is adopted as the flag of Canada, replacing the old Canadian Red Ensign banner.