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Last updated on May 26th, 2025

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Factors of 155

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A factor is a number that divides another number evenly without any remainder. We use factors for arranging items or dividing quantities evenly. Let’s learn and see what are the factors of 155.

Factors of 155 for UK Students
Professor Greenline from BrightChamps

What are the factors of 155?

Every number, except 1 and 0, will have a minimum of 2 factors. 


Factors of 155: 1,155, 5, 31
Negative factors of 155: -1,-155,-5,-31
Prime factorization of 155: 5×31
Sum of factors: 1+155+5+31=192
 

Professor Greenline from BrightChamps

How to find the factors of 155?

The methods mentioned below can be used to find the factors of 155. Use any factor-finding method that is easy for you. 


— Multiplication method 
— Division method 
— Prime factorization and prime factors method
— Factor tree method
 

Professor Greenline from BrightChamps

Finding Factors Using Multiplication

Find the pair of numbers which when multiplied gives 155.


155 is a composite number because it has more than 2 factors.


The factor pairs of 155 are


Positive factor pairs : (1,155) (5,31) 
Negative factor pairs : (-1,-155) (-5,-31)

Professor Greenline from BrightChamps

Finding Factors by Division Method

Start dividing 155 with small numbers and check the remainder.


Dividend = Divisor x Quotient + Remainder


The factors of 155 are 1,5,31,155 and -1,-5,-31,-155.
 

Professor Greenline from BrightChamps

Prime Factors and Prime Factorization

  • Prime factors of 155: 5,31

 

  • The prime factorization of 155= 5×31

 

  • The positive factors of 155 are 1,5,31,155. The negative factors are -1,-155,-5,-31.
     
Professor Greenline from BrightChamps

Factor tree

Factor tree is a graphical representation of breaking down any number into prime factors.


In case of 155, 


Step 1: First, we write the number on top (in this case, 155). From there, it will be broken down into 2 parts.


Step 2: Fill in the factor pairs of 155 in separate steps. In this step, the number will be factorized into 5 and 31.


Step 3: From this we can find that the prime factors of 5 and 31. This is how the factor tree helps students visualize the factors more easily.
 

Professor Greenline from BrightChamps

Factor Pairs

Factor pairs are a combination of two numbers, a and b, whose product is equal to 155. So, over here, a and b are a factor pair of 155.


The factor pairs of 155 are


Positive factor pairs -- (1,155) (5,31) 
Negative factor pairs -- (-1,-155) (-5,-31)

Max Pointing Out Common Math Mistakes

Common mistakes and how to avoid them in the factors of 155

It can get really tricky when trying to learn factors, and there is nothing to worry about. We will now take a look at some common mistakes made by students when learning factors. 

Mistake 1

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Students Can Think Factors Can Only be Small Numbers

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To check factors for any number, it is suggested to start checking with the smallest prime numbers. In many cases, students may get confused that a number can not be factorized further. So it is always good to remember the multiples of few numbers.
 

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Factors of 155 Examples

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Max, the Girl Character from BrightChamps

Problem 1

If 155 students are divided equally into groups, what are the possible sizes of the groups?

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To determine the possible group sizes, we need the factors of 155:


The factors are 1, 5, 31, and 155. Therefore, the possible group sizes are:


1 student per group: 155 groups
5 students per group: 31 groups
31 students per group: 5 groups
155 students per group: 1 group
 

Explanation

 The possible sizes of the groups are: 1,5,31,155.

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Max, the Girl Character from BrightChamps

Problem 2

A teacher has 155 books. If she wants to arrange them into rows of equal size without any remainder, what are the different ways she can arrange the books?

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We already know the factors of 155 are 1,5,31 and 155. The teacher can arrange the books in:


1 row of 155 books
5 rows of 31 books
31 rows of 5 books
155 rows of 1 book
 

Explanation

Thus, the different ways she can arrange the books are 1,5,31,155.
 

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Max, the Girl Character from BrightChamps

Problem 3

Verify the factor pairs of 155.

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List of potential pairs: Consider (x, y) such that x×y=155


Starting with x=1: y=155


Then x=5: y=31


No other integers up to square root of 155 can form pairs that yield 155.


Confirmed pairs: Pairs are (1,155) and (5,31)


Final factor list: Factors are 1,5,31,155
 

Explanation

This is how we verify the factor pairs of the number 155. 
 

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FAQs on 155 factors

1. What is the factor tree of 155?

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2. What is the perfect square factorization of 155?

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3. What are the multiples of 155?

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4.Is 155 a multiple of 11?

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5.What is 155 square root?

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6.How can children in United Kingdom use numbers in everyday life to understand Factors of 155 ?

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7.What are some fun ways kids in United Kingdom can practice Factors of 155 with numbers?

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8.What role do numbers and Factors of 155 play in helping children in United Kingdom develop problem-solving skills?

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9.How can families in United Kingdom create number-rich environments to improve Factors of 155 skills?

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Professor Greenline from BrightChamps

Important Glossaries for Factors of 155

  • Factors: Factors are numbers that, when multiplied together, result in a given number.  Example: Factors of 12 are:1 × 12 = 12, 2 × 6 = 12, 3 × 4 = 12. Here, 1, 2, 6, 3, 4 and 12 are the factors of 12.

 

  • Greatest Common Factor (GCF): The greatest number that divides the given number exactly and is a common factor for the given number is called GCF. An example for GCF is: The GCF of 1500, 10, and 100 is 10. Because it is the greatest factor that is common for all three numbers.

 

  • Prime number: Any number greater than 1 and has only 2 factors is called a prime number. Example: 811/1 = 811 and 811/811 = 1. We can see that 811 can be divided exactly by only 2 numbers. Those two numbers are 1 and 811.

 

  • Divisor: Any number that divides another number exactly and leaves no remainder is called a divisor. When we divide 12 by 3, we get a quotient of 4. Here, the divisor is 3 and the dividend is 12.
     
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About BrightChamps in United Kingdom

At BrightChamps, numbers are more than just figures—they open doors to endless opportunities! Our mission is to help children across the United Kingdom gain essential math skills, focusing today on Factors of 155 with special attention to understanding factors—in an engaging, enjoyable, and easy-to-follow way. Whether your child is working out the speed of a roller coaster at Alton Towers, keeping score at a local football match, or managing pocket money to buy the latest gadgets, strong number skills give them confidence in daily life. Our interactive lessons make learning simple and fun. Because children in the UK have varied learning styles, we tailor our approach to suit each learner. From London’s busy streets to Cornwall’s beautiful coasts, BrightChamps brings math to life, making it relatable and exciting throughout the UK. Let’s make factors an enjoyable part of every child’s math journey!
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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.

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Fun Fact

: She loves to read number jokes and games.

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