Factors of 20 are the collection of numbers which when multiplied in pairs give the product as 20. There are 6 factors of 20 in all and they can be negative as well. The number 20 is an even composite number, which means that it has several factors. Did you know that 20 is the atomic number of Calcium? In this lesson, we will explore the factors of 20, its prime factors, and its factors in pairs. We will also take a look at a few solved examples to better understand the factors of 20.

**Factors of 20:**1, 2, 4, 5, 10 and 20**Factors of -20:**-1, -2, -4, -5, -10 and -20**Prime Factorization of 20:**20 = 2^{2}× 5

**Table of Contents**

- What are Factors of 20?
- How to Calculate the Factors of 20?
- Important Notes
- Factors of 20 by Prime Factorization
- Challenging Questions
- Factors of 20 in Pairs
- Tips and Tricks
- FAQs on Factors of 20
- Factors of 20 Solved Examples
- Interactive Questions

## What are Factors of 20?

A factor is a number that divides the number into equal parts. Factors of 20 are the numbers which divide 20 completely without leaving any remainder. 4 and 5 are the factors of 20, that is, 5 divides 20 into equal parts of 4 each.

20 does not have 4 and 5 as its only factors. It has other factors as well which we will show you in the next section.

## How to Calculate the Factors of 20?

Follow the steps to calculate the factors of 20:

**Step 1:**Write down the number to be factored, i.e., 20.**Step 2:**Find the numbers which can divide 20 exactly without leaving any remainder.- 20 ÷ 1 = 20 Remainder 0
- 20 ÷ 2 = 10 Remainder 0
- 20 ÷ 3 = 6 Remainder 2

**Step 3:**Continue for rest of the numbers.

We see that 3 does not divide 20 completely and leaves a remainder. Therefore, 3 is not a factor. Continuing further, the numbers 1, 2, 4, 5, 10, and 20 leave no remainder. Hence, the **factors of 20 are 1, 2, 4, 5, 10, and 20.**

**Important Notes:**

- Factors of a number are all the possible numbers it is divisible by.
- They may be
**prime numbers**or**composite numbers**. - Factors can never be fractions or decimals.
- Factors can be negative integers.

**Explore factors using illustrations and interactive examples**

- Factors of 36 - The factors of 36 are 1, 2, 3, 4, 6, 9, 12, 18, 36.
- Factors of 24 - The factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24.
- Factors of 15 - The factors of 15 are 1, 3, 5, 15.
- Factors of 16 - The factors of 16 are 1, 2, 4, 8,16.
- Factors of 320 - The factors of 320 are 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 160, 320.
- Factors of 200 - The factors of 200 are 1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, and 200.

## Factors of 20 by Prime Factorization

**Prime factorization** is the process of writing a number as the product of its prime factors. Factors of 20 by prime factorization are found using the following steps:

Write the pair of factors which on multiplication gives the required number. 20 can be factored as a product of 4 and 5. Check the factors to see if each one of them is prime or not.

**Step 1:**4 is not a prime number and can be factored further as a 2 × 2.**Step 2:**5 is a prime number and it cannot be factored further.**Step 3:**Prime factorization of 20 can thereby be written as: 20 = 4 × 5 = 2 × 2 × 5**Step 4:**It can also be written in exponent form as 20 = 2^{2}× 5

**Challenging Questions:**

Jenny has an apple tree. She plucks 20 apples from the tree. She has to distribute it among her 4 friends. How many apples will each friend get?

## Factors of 20 in Pairs

The pair of numbers which give 20 as the result when multiplied are the** pair factors of 20.** Let's try visualizing it using blocks:

**The pair factors of 20 are:**

Factors |
Pair Factors |

1 × 20 = 20 | 1,20 |

2 × 10 = 20 | 2,10 |

4 × 5 = 20 | 4,5 |

5 × 4 = 20 | 5,4 |

10 × 2 = 20 | 10,2 |

20 × 1 = 20 | 20,1 |

The above-given factors are **positive pair factors**. It is possible to have negative pair factors as well because the product of two negative numbers gives a positive number. Let's take a look at the **negative pair factors of 20:**

Factors |
Pair Factors |

-1 × -20 = 20 | -1,-20 |

-2 × -10 = 20 | -2,-10 |

-4 × -5 = 20 | -4,-5 |

-5 × -4 = 20 | -5,-4 |

-10 × -2 = 20 | -10,-2 |

-20 × -1 = 20 | -20,-1 |

**Tips and Tricks:**

- The smallest factor of every number is 1.
- Every number has a minimum of 2 factors, i.e. 1 and the number itself.
- All
**even numbers**have 2 as one of their factors. - All numbers which end in 5 will have 5 as one of their factors.
- All numbers which end in 0 will have 1, 2, 5, and 10 as their factors.

## FAQs on Factors of 20

### What are Factors of 20?

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

### What are Common Factors of 20 and 30?

The factors of 20 are 1, 2, 4, 5, 10, and 20 and the factors of 30 are 1, 2, 3, 5, 6, 10, 15, and 30.

Thus, the common factors are 1, 2, 5, and 10.

### What are the Common Factors of 20 and 28?

The factors of 20 are 1, 2, 4, 5, 10, and 20. Similarly, the factors of 28 are 1, 2, 4, 7, 14, and 28.

Thus, the **common factors** are 1, 2, and 4.

### What are Factors of 20 and 24?

The factors of 20 are 1, 2, 4, 5, 10, and 20. The factors of 24 are 1, 2, 3, 4, 6, 8, 12, and 24.

### What are the Factors of 27?

The factors of 27 are 1,3,9 and 27.

## Factors of 20 Solved Examples

**Example 1: **Four friends plucked 20 mangoes from a tree and distributed the fruits among themselves equally.

How many would each one of them get?

**Solution:**

20 mangoes are to be divided among 4 friends equally. This implies that we need to divide 20 by 4 therefore 20 ÷ 4 = 5.

Thus, each person will get 5 mangoes.

**Example 2:** A rectangle has an area of 20 square inches and a length of 10 inches. Determine its breadth.

**Solution:**

The area of the rectangle can be calculated by the **formula : length × breadth.** The length of the rectangle, i.e.,10 inches is a factor of the area, i.e., 20 square inches.

When 2 is multiplied by 10, the product is 20 which can be written as 2 × 10 = 20. Thus, the breadth of the rectangle is 2 inches.

## Interactive Questions

**Here are a few activities for you to practice. **

**Select/Type your answer and click the "Check Answer" button to see the result.**