Fatto matematico: 1730 is the sum of consecutive squares in 2 ways.
Trivia: 1730 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: September 25th is the day in 1690 that Publick Occurrences Both Foreign and Domestick, the first newspaper to appear in the Americas, is published for the first and only time.