Fait mathématique: 1730 is the sum of consecutive squares in 2 ways.
Culture générale: 1730 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: September 25th is the day in 1959 that Solomon Bandaranaike, Prime Minister of Sri Lanka is mortally wounded by a Buddhist monk, Talduwe Somarama, and dies the next day.