The number 7 is often considered lucky, and it has a definite mystique, perhaps because it is a prime number—that is, it cannot be obtained by multiplying two smaller numbers together. There are seven days of the week, named after various ancient gods and planets, In ancient Egypt there were seven paths to heaven and seven heavenly cows. Breaking a mirror leads to seven years of bad luck and in both Islam and Judaism, there are seven heavens. Muslim people walk around the Kaaba seven times while making the pilgrimage to Mecca. Seven represents harmony encompassed by yin, yang, and the five elements in Confucianism.