Fatto matematico: 20411 is an uninteresting number.
Trivia: 20411 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: November 18th is the day in 1930 that Soka Kyoiku Gakkai, a Buddhist association later renamed Soka Gakkai, is founded by Japanese educators Tsunesaburo Makiguchi and Josei Toda.