General fact: 2678 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 2678 is the number of connected graphs with 10 vertices and 11 edges.
Trivia: 2678 is an uninteresting number.
Historical date: May 1st is the day in 1933 that the Roca-Runciman Treaty between Argentina and Great Britain is signed by Julio Argentino Roca, Jr., and Sir Walter Runciman.