Fatto matematico: 1684 is the number of multigraphs with 6 vertices and 9 edges.
Trivia: 1684 is a boring number.
Data storica: August 10th is the day in 1932 that a 5.1 kilograms (11 lb) chondrite-type meteorite breaks into at least seven pieces and lands near the town of Archie in Cass County, Missouri.