Fatto generale: 83684 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 83684 is an uninteresting number.
Trivia: 83684 is an unremarkable number.
Data storica: February 12th is the day in 2002 that an Iran Air Tours Tupolev Tu-154 crashes in the mountains outside Khorramabad, Iran while descending for a landing at Khorramabad Airport, killing 119.