Fait mathématique: 9821 is an uninteresting number.
Culture générale: 9821 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: November 20th is the day in 1994 that the Angolan government and UNITA rebels sign the Lusaka Protocol in Zambia, ending 19 years of civil war (localized fighting resumes the next year).