Last updated on May 26th, 2025
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.
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
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
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)
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.
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.
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)
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.
If 155 students are divided equally into groups, what are the possible sizes of the groups?
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
The possible sizes of the groups are: 1,5,31,155.
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?
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
Thus, the different ways she can arrange the books are 1,5,31,155.
Verify the factor pairs of 155.
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
This is how we verify the factor pairs of the number 155.
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.
: She loves to read number jokes and games.