These are the integers which can be evenly divided into 21; they can be expressed as either individual factors or as factor pairs. In this case, we present them both ways.
A prime factorization is the result of factoring a number into a set of components which are all prime numbers. This is generally written by showing 21 as a product of its prime factors. For 21, this result would be:21 = 3 x 7
Yes! 21 is a composite number. It is the product of two positive numbers other than 1 and itself.
No! 21 is not a square number. The square root of this number (4.58) is not an integer.
This number has 4 factors: 1, 3, 7, 21
More specifically, shown as pairs...
(1*21) (3*7) (7*3) (21*1)