"Sixteen" redirects here. For other uses, see Sixteen 16 (sixteen) is the natural number following 15 and preceding 17. Sixteen is a composite number, and a square number, being 4^2 = 4 × 4. It is the tiniest number with exactly five divisors, its proper divisors being , , and . As a power of 2 it has an aliquot sum one less than itself; 15, and is the fifth composite member of the 3-aliquot tree having the 7 member aliquot sequence (16,15,9,4,3,1,0).It is the fourth power of two. For this reason, 16 was used in weighing light objects in several cultures. The British used to have 16 ounces in one pound, the Chinese used to have 16 langs in one jin. In old days, weighing was done with a beam balance to make equal splits. It would be easier to split a heap of grains into sixteen equal parts through successive divisions than to split into ten parts. Chinese Taoists did finger computatio