Seven is the optimum number of hours of sleep for humans, according to a US scientific study.
Seven is seen as a lucky number in many cultures. Japanese mythology talks of Shichifukujin (The Seven Gods of Fortune).
The seven deadly sins, or cardinal sins, were refined by Pope Gregory I in the 6th century. They are pride, avarice, lust, envy, gluttony, wrath, and sloth.
The average person's digit span (the number of digits they can recall in sequence) is seven.
According to Buddhist legend, after his birth the Buddha rose to his feet and took seven steps.
The opposite faces of a dice add up to seven.
Seven segments make up each digit on the simplest electronic clock or calculator displays.
When asked to think of a number between one and 10, most people pick seven.