Fatto generale: 1734 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 1734 is the sum of its proper divisors that contain the digit 8.
Trivia: 1734 is an unremarkable number.
Data storica: September 29th is the day in 1227 that Frederick II, Holy Roman Emperor, is excommunicated by Pope Gregory IX for his failure to participate in the Crusades.