Mathematical fact: 691 is the smallest prime p for which x^{5} = x^{4} + x^{3} + x^{2} + x + 1 (mod p) has 5 solutions.
Trivia: 691 is an unremarkable number.
Historical date: November 21st is the day in 1979 that the United States Embassy in Islamabad, Pakistan is attacked by a mob and set on fire, killing four.