Fatto generale: 21101 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 21101 is a boring number.
Trivia: 21101 is an uninteresting number.
Data storica: October 8th is the day in 1895 that Eulmi incident- Queen Min of Joseon, the last empress of Korea, is assassinated and her corpse burnt by the Japanese in Gyeongbok Palace.