Fatto generale: 7874 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 7874 is the smallest number n for which n concatenated with n+2 is a square.
Trivia: 7874 is an uninteresting number.
Data storica: July 22nd is the day in 1793 that Alexander Mackenzie reaches the Pacific Ocean becoming the first Euro-American to complete a transcontinental crossing of Canada.