General fact: 2743 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 2743 is a centered dodecahedral number.
Trivia: 2743 is an unremarkable number.
Historical date: July 5th is the day in 1998 that Japan launches a probe to Mars, and thus joins the United States and Russia as a space exploring nation.