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323 LearnersLast updated on December 17, 2025
Factors of 20
Factors are the numbers that divide any given number evenly without remainder. In daily life, we use factors for tasks like sharing items equally, arranging things, etc. In this topic, we will learn about the factors of 20, how they are used in real life, and tips to learn them quickly.
What are the Factors of 20?
The numbers that divide 20 evenly are known as factors of 20. A factor of 20 is a number that divides the number without remainder.
The factors of 20 can be written as shown in the table given below:
| Factor Type | Values |
| Positive Factors of 20 | 1, 2, 4, 5, 10, 20 |
| Negative Factors of 20 | -1, -2, -4, -5, -10, -20 |
| Prime Factors of 20 | 2, 5 |
| Prime Factorization of 20 | 2 × 2 × 5 = 2² × 5 |
| The Sum of the Factors of 20 | 42 |
How to Find Factors of 20?
Factors can be found using different methods. Mentioned below are some commonly used methods:
1. Finding factors using multiplication
2. Finding factors using the division method
3. Prime factors and Prime factorization
Finding Factors Using Multiplication
To find factors using multiplication, we need to identify the pairs of numbers that are multiplied to give 20.
Identifying the numbers which are multiplied to get the number 20 is the multiplication method.
Step 1: Multiply 20 by 1, 20 × 1 = 20.
Step 2: Check for other numbers that give 20 after multiplying
2 × 10 = 20,
4 × 5 = 20
Therefore, the positive factor pairs of 20 are: (1, 20), (2, 10), (4, 5).
All these factor pairs result in 20. For every positive factor, there is a negative factor.
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Finding Factors Using Division Method
Dividing the given numbers with the whole numbers until the remainder becomes zero and listing out the numbers which result as whole numbers as factors.
Factors can be calculated by following a simple division method:
Step 1: Divide 20 by 1, 20 ÷ 1 = 20.
Step 2: Continue dividing 20 by the numbers until the remainder becomes 0.
20 ÷ 1 = 20
20 ÷ 2 = 10
20 ÷ 4 = 5
20 ÷ 5 = 4
Therefore, the factors of 20 are: 1, 2, 4, 5, 10, 20.
Prime Factors and Prime Factorization
The factors can be found by dividing them with prime numbers. We can find the prime factors using the following methods:
- Using prime factorization,
- Using a factor tree,
- Using Prime Factorization.
In this process, prime factors of 20 divide the number to break it down in the multiplication form of prime factors till the remainder becomes 1.
20 ÷ 2 = 10
10 ÷ 2 = 5
5 ÷ 5 = 1
The prime factors of 20 are 2 and 5.
The prime factorization of 20 is: 2² × 5.
Prime Factors of 20
Prime Factorization of 20
Factor Tree of 20
The factor tree is the graphical representation of breaking down any number into prime factors. The following step shows:
Step 1: Firstly, 20 is divided by 2 to get 10.
Step 2: Now divide 10 by 2 to get 5.
Here, 5 is the smallest prime number, that cannot be divided anymore.
So, the prime factorization of 20 is: 2² × 5
Factor Pairs of 20
The factors of 20 can be written in both positive and negative pairs. The table below represents the factor pairs of 20, where the product of each pair of numbers is equal to 20.
Positive Pair Factors of 20:
| Factors | Positive Pair Factors |
| 1 × 20 = 20 | 1, 20 |
| 2 × 10 = 20 | 2, 10 |
| 4 × 5 = 20 | 4, 5 |
Since the product of two negative numbers is also positive, 20 also has negative pair factors.
Negative Pair Factors of 20:
| Factors | Negative Pair Factors |
| −1 × −20 = 20 | −1, −20 |
| −2 × −10 = 20 | −2, −10 |
| −4 × −5 = 20 | −4, −5 |
Common Mistakes and How to Avoid Them in Factors of 20
Mistakes are common while finding factors. We can identify and correct those mistakes using the following common mistakes and the ways to avoid them.
Mistake 1
Forgetting the number itself and 1 is a factor
Children might forget to add the given number itself and 1 as a factor. The number itself and 1 are the factors for every word. Always remember to include 1 and the number itself. For example, in factors of 20, 1 and 20 are also factors.
Mistake 2
Missing Negative Factors
We have used only to mention positive factors every time. There are also negative factors, always check whether you have mentioned negative factors. For example, the factors of 20 consist of -1, -2, -4, etc.
Mistake 3
Including the Fraction
Children might sometimes add fractions also as factors. Only whole numbers can be a factor. For example, thinking 1.5 as a factor, because 20/1.5 = 13.333, and it is not a whole number.
Mistake 4
Confusing Factors With Prime Numbers
Remember that factors can be any whole numbers, not only just primes. For example, thinking all the factors of 20 are prime numbers. For example, 2 and 5 are the prime factors of 20, but it has other factors like 4, 10.
Mistake 5
Mistake in Factorization
Children might skip the steps in factorization and end up writing wrong factors. For example, not breaking 20 as 2² × 5 and missing all the key factors.
Examples on Factors of 20
Problem 1
There are 4 friends and 20 pencils. How will they divide it equally?
They will get 5 pencils each.
Explanation
To divide the pencils equally, we need to divide the total pencils with the number of friends. 20/4 = 5
Problem 2
A garden is rectangular, the length of the garden is 5 meters and the total area is 20 square meters. Find the width?
4 meters.
Explanation
To find the width of the garden, we use the formula, Area = length × width 20 = 5 × width To find the value of width, we need to shift 5 to the left side. 20/5 = width Width = 4.
Problem 3
At a Walmart in Dallas, a teacher is preparing snack packs for a school science fair. She has 20 granola bars and wants to divide them equally into gift bags with no leftovers. Which numbers of gift bags are possible?
1, 2, 4, 5, 10, 20
Explanation
To divide the 20 granola bars equally, the number of gift bags must be a factor of 20.
Factors are numbers that divide 20 exactly without leaving a remainder.
The factors of 20 are 1, 2, 4, 5, 10, and 20, so she can create any of these numbers of equal gift bags.
Problem 4
In Los Angeles, gas costs $5 per gallon. A driver spends $20 at the gas station. How many whole gallons of gas could the driver buy?
4 gallons
Explanation
To find the number of gallons, divide the total cost by the price per gallon.
Since 20 ÷ 5 = 4, and 5 is a factor of 20, the driver can buy exactly 4 gallons without any leftover money.
Problem 5
A pharmacist at CVS in Boston receives 20 tablets of a vitamin supplement. The tablets must be packed into bottles with the same number of tablets in each bottle, with none left over. What are all the possible ways to pack the tablets?
1, 2, 4, 5, 10, 20
Explanation
To pack the tablets evenly, the number of tablets per bottle must be a factor of 20.
Since 1, 2, 4, 5, 10, and 20 divide 20 exactly, these are all the possible packing options.
FAQs on Factors of 20
1.What are the factors of 20?
2.Mention the prime factors of 20.
3.Is 20, a multiple of 4?
4.Mention the factor pairs of 20?
5.What is the square of 20?
6.How many factors does 20 have?
7.What is the smallest factor of 20?
8.What is the largest factor of 20?
9.Which factors of 20 add up to 13?
10.How many even factors does 20 have?
11.What are the odd factors of 20?
12.What is the sum of all the factors of 20?
Important Terms Related to Factors of 20
- Factors: The numbers that divide the given number without leaving a remainder are called factors.
For example, the factors of 20 are 1, 2, 4, 5, 10, and 20.
- Prime factors: The factors which are prime numbers.
For example, 2 and 5 are prime factors of 20.
- Factor pairs: Two numbers in a pair that are multiplied to give the original number are called factor pairs.
For example, the factor pairs of 20 are (1, 20), (2, 10), etc.
- Multiple: A number that can be divided by another number without a remainder.
For example, 20 is a multiple of 4.
- Divisor: A number by which another number is to be divided. In the context of factors, divisors are the same as factors.
For example, 4 is a divisor of 20.
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Hiralee Lalitkumar Makwana
About the Author
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
Fun Fact
: She loves to read number jokes and games.
