# Factors of 20 – With Division and Prime Factorization

## Factors Of 20

Factors of 20 are the numbers that result in 20 when two factors are multiplied together. They are 1,2,4,5,10 and 20. When multiplied together, these factor pairs produce the original number.

We will use the factorization method to find the factors of a number, 20. As part of the factorization method, evaluate 1 and 20 as factors first and then find the other pair of multiples of 20 resulting in the original number.

You can read the following article to understand this method better by finding the factors of 20 in pairs. Additionally, this article explores the prime factors of 20 using prime factorization.

## What are the Factors of 20?

A factor of 20 is a number that divides 20 exactly with no remainder. Thus, the factors of 20 are multiplied in pairs resulting in the number 20.

20 has many factors besides 1 and 20 because it is an even number. Therefore, 20 has factors 1, 2, 4, 5, 10, and 20. Likewise, the negative factors of 20 are -1, -2, -4, -5, -10 and -20.

Factors of 20: 1, 2, 4, 5, 10, and 20.

Prime Factorization of 20: 2 × 2 × 5 or 22 × 5

## Pair Factors of 20

In addition to being a positive number, the factor of 20 can also be a negative number. It is, therefore, possible to have a pair factor of 20 both in positive and negative pairs.

The pair factor of 20 is a pair of numbers that, when multiplied together,result in 20. Here are the positive and negative pair factors of 20:

Positive Pair Factor of 20:

Negative Pair Factor of 20:

## Factors of 20 by Division Method

By dividing 20 by different integers, we can find the factors of 20. Integers that divide 20 exactly, leaving the remainder 0, then they are factors of 20. We will now discuss the factors of 20 by division.

• 20/1 = 20
• 20/2 = 10
• 20/4 = 5
• 20/5 = 4
• 20/10 = 2
• 20/20 = 1

When we divide 20 by other numbers than 1, 2, 4, 5, and 10, it leaves a remainder. Accordingly, the factors of 20  are 1, 2, 4, 5, 10, and 20.

## Prime Factorization of 20

As a result of a prime factorization, the number 20 is written as the product of its prime factors. In addition to being a composite number, 20 can be factorized and written as a product of prime factors. The following steps will show you how to identify 20’s prime factors.

For example, (1, 20) is a pair factor.

We cannot factor the number 1 further since it is neither prime nor composite.

Let’s look at the number 20, and it is a composite number.

Therefore, divide the number 20 into its prime factors.

You can write 20 as follows:

20 = 4 × 5

In this case, 5 is a prime number, while 4 is a composite number that you can further factor.

Thus, 20 = 2 × 2 × 5

Consequently, the prime factorization of 20 is 2 × 2 × 5 or 22 × 5.

## Examples

Example 1:

What are the common factors of 20 and 21?

Solution:

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

Factors of 21 = 1, 3, 7, and 21.

Therefore, 20 and 21 have a common factor of 1.

Example 2:

Calculate the common factors of 20 and 19.

Solution:

Factors of 20 = 1, 2, 4, 5, 10 and 20.

1 and 19 are the factors of 19.

Since 19 is a prime number, the common factor between 20 and 19 is only 1.

Example 3:

Find the common factor between 20 and 40.

Solution:

There are six factors of 20: 1, 2, 4, 5,10,  and 20.

One, two, four, five, eight, ten, twenty, and forty are the factors of 40.

Thus, 20 and 40 have the same factors of 1, 2, 4, 5, 10, and 20.

## FAQs

### How many factors are there in 20?

Factors of 20 include 1, 2, 4, 5, 10, and 20.

### How does 20 factorize into prime factors?

Prime factorization of 20 is 2 × 2 × 5 or 22 × 5.

### List the positive pair factors of 20.

There are three positive pair factors of 20: (1, 20), (2, 10), and (4, 5).

### How many negative pair factors does 20 have?

There are three negative pair factors for 20: (-1, -20), (-2, -10), (-4, -5).

### Is 5 a factor of 20?

5 is indeed a factor of 20. When 5 divides 20, the remainder is 0, so 5 is a factor of 20.