General fact: 86811 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 86811 is an uninteresting number.
Trivia: 86811 is an unremarkable number.
Historical date: September 5th is the day in 1980 that the St. Gotthard Tunnel opens in Switzerland as the world's longest highway tunnel at 10.14 miles (16.224 km) stretching from Göschenen to Airolo.