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# Factors of 85

In Mathematics, factors of 85 are the natural numbers that can be written in product form to get the original number. These factors divide the original number into equal numbers of parts. For example, 85 is divisible by 5 (by divisibility rules). So, 85 divided by 5 is equal to 17. Hence, 5 divides the number 85 into 17 equal parts.

In the same way, we can determine the other factors of 85 with the help of the division method. 85 has more than two factors, thus it is a composite number. Let us find the pair factors and prime factors of the number 85, here at BYJU’S.

 Factors Pair Factors Prime Factors Form 1, 5, 17 and 85 (1, 85) and (5, 17) 85 = 5 x 17

## How to Find the Factors of 85?

When the product of two natural numbers results in 85, then the two numbers are the factors. We already know that 1 is the factor of all the natural numbers and also, the original number is the factor of itself.

85 ÷ 1 = 85

85 ÷ 5 = 17

85 ÷ 17 = 5

85 ÷ 85 = 1

Therefore, the factors of 85 are 1, 5, 17 and 85.

## Pair Factors of 85

The multiplication of pair factors of a number results in the original number. Therefore, the product of factors in pairs that results in 85 are:

1 × 85 = 85

5 × 17 = 85

Therefore, the pair factors are (1, 85) and (5, 17).

We can also write the pair factors in negative terms, since the product of two negative factors will result in the positive number.

-1 × -85 = 85

-5 × -17= 85

Therefore, the negative pair factors are (-1, -85), and (-5, -17).

## Prime Factorisation of 85

Prime factors of 85 are the prime numbers that can divide the original number completely. The prime factorisation method will help to produce the prime factors. Since 85 is a composite number, we can represent the number 85 as a product form of prime numbers.

In the prime factorisation method, we divide the original number by prime numbers that will not result in any remainder. Let us list down the prime numbers between 1 and 85.

List of prime numbers (Between 1 and 85) :

 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83

From the above list we will be finding the prime factors that can divide 85.

Step 1: 85 is divisible by 5.

85/5 = 17

Step 2: 17 is a prime number and divisible by itself only.

17/17= 1

Thus, we have received 1 as the value and it is not divisible by any prime number. Therefore, the required prime factors are 5 and 17.

 Prime factorisation of 85 = 5 x 17 Exponential Form = 51 x 171

## Solved Examples

Q.1: What is the value of 85 divided by 17?

Solution: 85 divided by 17 = 85 ÷ 17 = 5

Q.2: Find the sum of all the factors of 85.

Solution: The factors of 85 are 1, 5, 17 and 85.

Sum = 1 + 5 + 17+ 85 = 108

Therefore, the sum of factors of 85 is 108.

Q.3: Find the GCF of 85 and 100.

Answer: Let us first write the factors of both numbers.

85 → 1, 5, 13, 85

100 → 1, 2, 4, 5, 10, 20, 25, 50, 100

Therefore, the greatest common factor (GCF) of 85 and 100 = 5

### Practice Questions

1. Calculate the average value of factors of 85.

2. What is the LCM of 85 and 100?

3. Find the GCF of 85, 75 and 95.

4. Is 85 an even number or odd number?

5. What is the value of 85 multiplied by 20?

## Frequently Asked Questions on Factors of 85

### What are the factors of 85?

The factors of 85 are 1, 5, 17 and 85.

### What are the multiples of 85?

The multiples of 85 are 85, 170, 255, 340, 425, 510, 595, 680, 765 and 850. We can find the multiples by multiplying 85 by the next consecutive natural numbers.

### What is the greatest prime factor of 85?

The greatest prime factor of 85 is 17.

### Is 85 a prime or composite number?

85 is a composite number since it has more than two factors.

### Is 85 a perfect square?

85 is not a perfect number or perfect square. The square root of 85 will produce a whole number but a fraction.

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