# Factors of 645

Factors of 645 are 1, 3, 5, 15, 43, 129, 215, and 645

#### How to find factors of a number

 1.   Find factors of 645 using Division Method 2.   Find factors of 645 using Prime Factorization 3.   Find factors of 645 in Pairs 4.   How can factors be defined? 5.   Frequently asked questions 6.   Examples of factors

### Example: Find factors of 645

• Divide 645 by 1: 645 ÷ 1 : Remainder = 0
• Divide 645 by 3: 645 ÷ 3 : Remainder = 0
• Divide 645 by 5: 645 ÷ 5 : Remainder = 0
• Divide 645 by 15: 645 ÷ 15 : Remainder = 0
• Divide 645 by 43: 645 ÷ 43 : Remainder = 0
• Divide 645 by 129: 645 ÷ 129 : Remainder = 0
• Divide 645 by 215: 645 ÷ 215 : Remainder = 0
• Divide 645 by 645: 645 ÷ 645 : Remainder = 0

Hence, Factors of 645 are 1, 3, 5, 15, 43, 129, 215, and 645

#### 2. Steps to find factors of 645 using Prime Factorization

A prime number is a number that has exactly two factors, 1 and the number itself. Prime factorization of a number means breaking down of the number into the form of products of its prime factors.

There are two different methods that can be used for the prime factorization.

#### Method 1: Division Method

To find the primefactors of 645 using the division method, follow these steps:

• Step 1. Start dividing 645 by the smallest prime number, i.e., 2, 3, 5, and so on. Find the smallest prime factor of the number.
• Step 2. After finding the smallest prime factor of the number 645, which is 3. Divide 645 by 3 to obtain the quotient (215).
645 ÷ 3 = 215
• Step 3. Repeat step 1 with the obtained quotient (215).
215 ÷ 5 = 43
43 ÷ 43 = 1

So, the prime factorization of 645 is, 645 = 3 x 5 x 43.

#### Method 2: Factor Tree Method

We can follow the same procedure using the factor tree of 645 as shown below:

So, the prime factorization of 645 is, 645 = 3 x 5 x 43.

#### 3. Find factors of 645 in Pairs

Pair factors of a number are any two numbers which, which on multiplying together, give that number as a result. The pair factors of 645 would be the two numbers which, when multiplied, give 645 as the result.

The following table represents the calculation of factors of 645 in pairs:

Factor Pair Pair Factorization
1 and 645 1 x 645 = 645
3 and 215 3 x 215 = 645
5 and 129 5 x 129 = 645
15 and 43 15 x 43 = 645

Since the product of two negative numbers gives a positive number, the product of the negative values of both the numbers in a pair factor will also give 645. They are called negative pair factors.

Hence, the negative pairs of 645 would be ( -1 , -645 ) , ( -3 , -215 ) , ( -5 , -129 ) and ( -15 , -43 ) .

#### What are factors?

In mathematics, a factor is that number which divides into another number exactly, without leaving a remainder. A factor of a number can be positive or negative.

#### Properties of factors

• Every factor of a number is an exact divisor of that number, example 1, 3, 5, 15, 43, 129, 215, 645 are exact divisors of 645.
• Every number other than 1 has at least two factors, namely the number itself and 1.
• Each number is a factor of itself. Eg. 645 is a factor of itself.
• 1 is a factor of every number. Eg. 1 is a factor of 645.

• How do you find factors of a negative number? ( eg. -645 )?

Factors of -645 are -1, -3, -5, -15, -43, -129, -215, -645.

• What is the sum of all factors of 645?

The sum of all factors of 645 is 1056.

• What is prime factorization of 645?

Prime factorization of 645 is 3 x 5 x 43.

• What are the pair factors of 645?

Pair factors of 645 are (1,645), (3,215), (5,129), (15,43).

• What are six multiples of 645?

First five multiples of 645 are 1290, 1935, 2580, 3225, 3870, 4515.

• Is 645 a whole number?

Yes 645 is a whole number.

• Which is the smallest prime factor of 645?

Smallest prime factor of 645 is 3.

• What are five multiples of 645?

First five multiples of 645 are 1290, 1935, 2580, 3225, 3870.

• Write all factors of 645?

Factors of 645 are 1, 3, 5, 15, 43, 129, 215, 645.

#### Examples of Factors

Joey wants to write all the prime factors of 645 in exponential form, but he doesn't know how to do so can you assist him in this task?

Prime factors of 645 are 3, 5, 43.
So in exponential form it can be written as 3 x 5 x 43.

How many factors are there for 645?

Factors of 645 are 1, 3, 5, 15, 43, 129, 215, 645.
So there are in total 8 factors.

Kevin has been asked to write 7 factor(s) of 645. Can you predict the answer?

7 factor(s) of 645 are 1, 3, 5, 15, 43, 129, 215.

Sammy is puzzled while calculating the prime factors of 645. Can you help him find them?

Factors of 645 are 1, 3, 5, 15, 43, 129, 215, 645.
Prime factors of 645 are 3, 5, 43

What is prime factorization of 645?

Prime factorization of 645 is 3 x 5 x 43 = 3 x 5 x 43.

Ariel has been assigned the task to find the product of all the prime factors of 645. Can you help her?

Prime factors of 645 are 3, 5, 43.
Hence, the product of prime factors of 645.

Can you help Rubel to find out the product of the even factors of 645?

Factors of 645 are 1, 3, 5, 15, 43, 129, 215, 645.
Even factors of 645 are 0.
Hence, product of even factors of 645 is; 0 = 0.