What are the factors and prime factors of 20?

Answer 1

20 is a composite number; it has factors other than 1 and itself. It is not a Prime number.

The 6 factors of 20 are 1, 2, 4, 5, 10, and 20.

The factor pairs of 20 are 1 x 20, 2 x 10, and 4 x 5.

The proper factors of 20 are 2, 4, 5, and 10 or,

if the definition you are using excludes 1, they are 2, 4, 5, and 10.

The prime factors of 20 are 2, 2, and 5.

Note: There is repetition of these factors, so if the prime factors are being listed instead of the prime factorization, usually only the distinct prime factors are listed.

The 2 distinct prime factors (listing each prime factor only once) are 2 and 5.

The prime factorization of 20 is 2 x 2 x 5 or, in index form (in other words, using exponents), 22 x 5.

NOTE: There cannot be common factors, a greatest common factor, or a least common multiple because "common" refers to factors or multiples that two or more numbers have in common.
1, 2, 4, 5, 10, 20

2 and 5 are prime.
1, 2, 4, 5, 10, 20

2 and 5 are prime.
1, 2, 4, 5, 10, 20

2 and 5 are prime.