Fatto generale: 1738 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 1738 is 6952 / 4, and this equation uses each digit 1-9 exactly once.
Trivia: 1738 is an unremarkable number.
Data storica: 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.