general_fact: 1738 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 1738 is 6952 / 4, and this equation uses each digit 1-9 exactly once.
trivia: 1738 is an uninteresting number.
historical_date: October 3rd is the day in 1739 that the Treaty of Nissa is signed by the Ottoman Empire and Russia at the finish of the Russian-Turkish War, 1736–1739.