Prime Number Program in Python
Write a Program to get a number n and to find whether n is prime number or not. Generally Prime number is a number which cannot be divisible by any whole numbers except 1 and n.
Sample Input 1:
Sample Output 1:
Not a Prime Number
Sample Input 2:
Sample Output 2:
9 is divisible by 3
11 is only divisible by 1 and 11.
Program or Solution
#Python Program to find whether given number is Prime or Not
n = int(input("Enter a Number:")) #get input n
#check which are the numbers from 2 to n/2 divides n.
#No other after n/2 divides n except n
for i in range(2,n//2+1):
if n % i == 0: #if divisible then it is not prime.
print("It is Not a Prime Number")
else: #this is else of for statement. executes after last iteration if loop is not broken at any iteration.
print("It is a Prime Number")
input() gets the value of n from users as string, and int() coverts the same to integer.
The following for loop iterates from i = 1 to n/2, in each iteration it checks whether the n is divisible by i.
if i divides n then print "It is Not a Prime" and exit the loop through break statement. No other number after n/2 divides n except n.
Print "It is a Prime Number" after last iteration if loop iteration was not broken at any iteration.