General fact: 6 is the number of days taken to create the world by Yahweh in the Old Testament Book of Genesis, and the number of the day on which humankind were created.
Mathematical fact: 6 is a unitary perfect number, a harmonic divisor number and a highly composite number.
Trivia: 6 is the number of fundamental flight instruments lumped together on a cockpit display.
Historical date: January 6th is the day in 1449 that Constantine XI is crowned Byzantine-Roman Emperor at Mystras.