Prime Factors in Python

Prime factors in python | We will discuss how to python program find prime factors of a number. The number which has only two factors 1 and itself, those numbers are called the prime number.

Examples:-

  • Find the prime factors of a number 150.
  • The numbers 1, 2, 3, 5, 6, 10, 15, 25, 30, 50, 75, and 150 are complete divides number 150 so they are called the factor of 150.
  • In this numbers 2, 3, and 5 are prime factors of 150. Because these numbers are prime numbers.

Prime Factors of a Number in Python

This is the simplest and easiest way to find prime factors of a number program in python. We will take a number while declaring the variables. Python program to find prime factors of a number using for-loop and result will be displayed on the screen.

# Python program to find prime factors of a number
 
# take inputs
num = int(input('Enter number: '))

# find prime factors
for i in range(2, num + 1):
    if(num % i == 0):
        isPrime = 1
        for j in range(2, (i //2 + 1)):
            if(i % j == 0):
                isPrime = 0
                break
        if (isPrime == 1):
            print(i,end=' ')
print('are the prime factors of number',num)

Output for the different input values:-

Enter number: 35
5 7 are the prime factors of number 35

Enter number: 99
3 11 are the prime factors of number 99

Enter number: 150
2 3 5 are the prime factors of number 150

In this program, inputs are scanned using the input() function and stored in the variable num.

num = int(input('Enter number: '))

Python program to find prime factors of a number using for-loop and result will be displayed on the screen.

for i in range(2, num + 1):
    if(num % i == 0):
        isPrime = 1
        for j in range(2, (i //2 + 1)):
            if(i % j == 0):
                isPrime = 0
                break
        if (isPrime == 1):
            print(i,end=' ')
print('are the prime factors of number',num) 

Prime Factors Program using While Loop

In the previous program, find prime factors of a number using for loop but in this program, find prime factors of a number using while loop.

# Python program to find prime factors of a number
 
# take inputs
num = int(input('Enter number: '))

# find prime factors
i = 1
while(i <= num):
    count = 0
    if(num % i == 0):
        j = 1
        while(j <= i):
            if(i % j == 0):
                count = count + 1
            j = j + 1
        if (count == 2):
            print(i,end=' ')
    i = i + 1
    
print('are the prime factors of number',num)

Output:-

Enter number: 100
2 5 are the prime factors of number 100

Prime Factorization Python Program using Function

We can also take the help of a function to find the average of 3 numbers in python. A function is a block of code that performs a specific task.

# Python program to find prime factors of a number using function

def primeNumber(num):  # user defind function
    # find prime factors
    for i in range(2, num + 1):
        if(num % i == 0):
                isPrime = 1
                for j in range(2, (i //2 + 1)):
                    if(i % j == 0):
                        isPrime = 0
                        break
                if (isPrime == 1):
                    print(i,end=' ')
    print('are the prime factors of number',num)

# take inputs
num = int(input('Enter number: '))

# calling function
primeNumber(num)

Output:-

Enter number: 500
2 5 are the prime factors of number 500

In this program, we will be the first defined function.

def primeNumber(num):  # user defind function
    # find prime factors
    for i in range(2, num + 1):
        if(num % i == 0):
                isPrime = 1
                for j in range(2, (i //2 + 1)):
                    if(i % j == 0):
                        isPrime = 0
                        break
                if (isPrime == 1):
                    print(i,end=' ')
    print('are the prime factors of number',num)

Inputs are scanned using the input() function and stored in variable num. Then call the function and display the result.

# take inputs
num = int(input('Enter number: '))

# calling function
primeNumber(num)

Also See:- Leap Year Program in Python

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