Factors of 20

The factors of 20 are the numbers, which produce the result as 20 when a pair of factors are multiplied together. These factors are 1,2,4,5,10 and 20. Factor pairs of the number, that results in the original number when multiplied together. To find the factors of a number, 20, we will use the factorization method. In the factorization method, first consider the numbers, 1 and 20 as factors and continue with finding the other pair of multiples of 20 which gives the results as an original number. To understand this method in a better way, read the below article to find the factors of 20 in pairs. Also, the prime factors of 20 with the help of the prime factorization is discussed here.

Table of Contents:

• What are the Factors of 20?
• Pair Factors of 20
• Factors of 20 by Division Method
• Prime Factorization of 20
• Examples
• FAQs

What are the Factors of 20?

The factors of 20 are the numbers that divide 20 exactly without leaving a remainder. In other words, the numbers are multiplied in pairs resulting in the number 20 are the factors of 20. As 20 is an even composite number, it has many factors other than 1 and 20. Thus, the factors of 20 are 1, 2, 4, 5, 10 and 20. Similarly, the negative factors of 20 are -1, -2, -4, -5, -10 and -20.

Pair Factors of 20

We know that the factors of 20 can also be in negative form. Hence, the pair factor of 20 can also be in positive pairs as well as in negative pairs. A pair of numbers that on multiplication results in 20 is called the pair factor of 20. Thus, the positive and negative pair factors of 20 are given below:

Positive Pair Factor of 20:

Negative Pair Factor of 20:

Factors of 20 by Division Method

In the division method, the factors of 20 can be found by dividing 20 by different integers. If the integer divides 20 exactly and leaves the remainder 0, then the integers are the factors of 20. Now, let us discuss the factors of 20 by division method.

• 20/1 = 20 (Factor is 1 and Remainder is 0)
• 20/2 = 10 (Factor is 2 and Remainder is 0)
• 20/4 = 5 (Factor is 4 and Remainder is 0)
• 20/5 = 4 (Factor is 5 and Remainder is 0)
• 20/10 = 2 (Factor is 10 and Remainder is 0)
• 20/20 = 1 (Factor is 20 and Remainder is 0)

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

Prime Factorization of 20

In the prime factorization method, the number 20 is written as the product of its prime factors. As we know that the number 20 is a composite number and it can be further factored and written as the product of prime factors. Go through the following steps to find the prime factors of 20.

Take the pair factor of 20, say (1, 20)

As the number 1 is neither prime nor composite, it cannot be further factored.

Now, take the number 20, and it is a composite number.

So, split the number 20 into its prime factors. 

20 can be written as follows:

20 = 4 × 5

Here, 5 is a prime number and 4 is a composite number, which can be factored further.

Thus, 20 = 2 × 2 × 5

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

Video Lesson on Prime Factors

Examples

Example 1:

Find the common factors of 20 and 21.

Solution:

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

The factors of 21 are 1, 3, 7 and 21.

Thus, the common factor of 20 and 21 is 1.

Example 2:

Find the common factors of 20 and 19.

Solution:

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

Factors of 19 = 1 and 19.

As 19 is a prime number, the common factor of 20 and 19 is 1 only.

Example 3:

Find the common factors of 20 and 40.

Solution:

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

The factors of 40 are 1, 2, 4, 5, 8, 10, 20 and 40.

Hence, the common factors of 20 and 40 are 1, 2, 4, 5, 10 and 20.

Learn more about factors and prime factors of other numbers by downloading BYJU’S – The Learning App for a better experience and clarification.