Fait mathématique: 21057 is an uninteresting number.
Culture générale: 21057 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: August 25th is the day in 2003 that the Tli Cho land claims agreement is signed between the Dogrib First Nations and the Canadian federal government in Rae-Edzo (now called Behchoko).