Prime Numbers Program in Python

Prime numbers are fascinating mathematical entities which have intrigued mathematicians for hundreds of years. A first-rate quantity is a pure quantity larger than 1 that’s divisible solely by 1 and itself, with no different components. These numbers possess a singular high quality, making them indispensable in varied fields corresponding to cryptography, laptop science, and quantity idea. They’ve a mystique that arises from their unpredictability and obvious randomness, but they observe exact patterns and exhibit extraordinary properties. On this weblog, we are going to discover prime numbers and delve into the implementation of a chief quantity program in Python. By the top, you should have a strong understanding of prime numbers and the power to establish them utilizing the facility of programming. Let’s embark on this mathematical journey and unlock the secrets and techniques of prime numbers with Python!

What’s a chief quantity?

Prime numbers are a subset of pure numbers whose components are only one and the quantity itself. Why are we apprehensive about prime numbers and acquiring prime numbers? The place can they be presumably used? We will perceive your entire idea of prime numbers on this article. Let’s get began. 

The components for a given quantity are these numbers that lead to a zero the rest on division. These are of prime significance within the space of cryptography to allow private and non-private keys. Primarily, the web is steady at the moment due to cryptography, and this department depends closely on prime numbers. 

Is 1 a chief quantity?

Allow us to take a step again and pay shut consideration to the definition of prime numbers. They’re outlined as ‘the pure numbers larger than 1 that can not be shaped by multiplying two smaller pure numbers’. A pure quantity that’s larger than 1 however isn’t a chief quantity is named a composite quantity. 

Subsequently, we can not embrace 1 within the checklist of prime numbers. All lists of prime numbers start with 2. Thus, the smallest prime quantity is 2 and never 1.

Co-prime numbers

Allow us to be taught additional. What if we have now two prime numbers? What’s the relationship between any two prime numbers? The best widespread divisor between two prime numbers is 1. Subsequently, any pair of prime numbers leads to co-primes. Co-prime numbers are the pair of numbers whose best widespread issue is 1. We will even have non-prime quantity pairs and prime and non-prime quantity pairs. For instance, take into account the variety of pairs-

  1. (25, 36)
  2. (48, 65)
  3. (6,25)
  4. (3,2)

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Smallest and largest prime quantity

Now that we have now thought of primes, what’s the vary of the prime numbers? We already know that the smallest prime quantity is 2.

What could possibly be the biggest prime quantity?

Nicely, this has some fascinating trivia associated to it. Within the yr 2018, Patrick Laroche of the Nice Web Mersenne Prime Search discovered the biggest prime quantity, 282,589,933 − 1, a quantity which has 24,862,048 digits when written in base 10. That’s an enormous quantity. 

For now, allow us to give attention to implementing varied issues associated to prime numbers. These downside statements are as follows:

  1. Recognizing whether or not they’re prime or not
  2. Acquiring the set of prime numbers between a variety of numbers
  3. Recognizing whether or not they’re prime or not.

This may be finished in two methods. Allow us to take into account the primary technique. Checking for all of the numbers between 2 and the quantity itself for components. Allow us to implement the identical. At all times begin with the next algorithm-


  1. Initialize a for loop ranging from 2 and ending on the quantity 
  2. Test if the quantity is divisible by 2
  3. Repeat until the quantity -1 is checked for
  4. In case, the quantity is divisible by any of the numbers, the quantity isn’t prime
  5. Else, it’s a prime quantity
num = int(enter("Enter the quantity: "))
if num > 1:
# test for components
for i in vary(2,num):
if (num % i) == 0:
print(num,"isn't a chief quantity")
print(num,"is a chief quantity")
# if enter quantity is lower than
# or equal to 1, it's not prime
print(num,"isn't a chief quantity")

Allow us to take into account the environment friendly resolution, whereby we will scale back the computation into half. We test for components solely till the sq. root of the quantity. Think about 36: its components are 1,2,3,4,6,9,12,18 and 36.

Sq. root of 36 is 6. Till 6, there are 4 components aside from 1. Therefore, it’s not prime.

Think about 73. Its sq. root is 8.5. We spherical it off to 9. There aren’t any components aside from 1 for 73 until 9. Therefore it’s a prime quantity.

Now earlier than we get into the main points of Python Program for prime quantity, possibly get a free refresher course on the Fundamentals of Python. This course covers all the fundamental and superior ideas of Python programming like Python Knowledge Constructions, Variables, Operators, Movement Management Statements, and OOPs. It even gives a certificates on completion which may undoubtedly increase your resume.

Python Program for prime quantity

Allow us to implement the logic in python–


  1. Initialize a for loop ranging from 2 ending on the integer worth of the ground of the sq. root of the quantity 
  2. Test if the quantity is divisible by 2
  3. Repeat until the sq. root of the quantity is checked for.
  4. In case, the quantity is divisible by any of the numbers, the quantity isn’t prime
  5. Else, it’s a prime quantity
import math
def primeCheck(x):
sta = 1
for i in vary(2,int(math.sqrt(x))+1): # vary[2,sqrt(num)]
print("Not Prime")
return sta
num = int(enter("Enter the quantity: "))
ret = primeCheck(num)

We outline a perform primeCheck which takes in enter because the quantity to be checked for and returns the standing. Variable sta is a variable that takes 0 or 1.

Allow us to take into account the issue of recognizing prime numbers in a given vary:


  1. Initialize a for loop between the decrease and higher ranges
  2. Use the primeCheck perform to test if the quantity is a chief or not
  3. If not prime, break the loop to the subsequent outer loop
  4. If prime, print it.
  5. Run the for loop until the upperRange is reached.
l_range = int(enter("Enter Decrease Vary: "))
u_range = int(enter("Enter Higher Vary: "))
print("Prime numbers between", l_range, "and", u_range, "are:")
for num in vary(l_range, u_range + 1):
# all prime numbers are larger than 1
if num > 1:
for i in vary(2, num):
if (num % i) == 0:

On this tutorial, we have now lined each matter associated to prime numbers. We hope you loved studying the article. For extra articles on machine studying and python, keep tuned!

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