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Python Program to Check Prime NumberWe will write a program here in which we will check that a given number is a prime number or not. Prime numbers: If the natural number is greater than 1 and having no positive divisors other than 1 and the number itself etc. For example: 3, 7, 11 etc are prime numbers. Composite number: Other natural numbers that are not prime numbers are called composite numbers. For example: 4, 6, 9 etc. are composite numbers. Let us look at the following example to understand the implementation. Example:# A default function for Prime checking conditions def PrimeChecker(a): # Checking that given number is more than 1 if a > 1: # Iterating over the given number with for loop for j in range(2, int(a/2) + 1): # If the given number is divisible or not if (a % j) == 0: print(a, "is not a prime number") break # Else it is a prime number else: print(a, "is a prime number") # If the given number is 1 else: print(a, "is not a prime number") # Taking an input number from the user a = int(input("Enter an input number:")) # Printing result PrimeChecker(a) Output: Enter an input number:17 17 is a prime number Explanation: We have used nested if else condition to check if the number is a prime number or not. First, we have checked if the given number is greater than 1 or not. If it is not greater than 1, then the number will directly come to the else part and print 'not a prime number.' Now, the number will enter into for loop where we perform Iteration from 2 to number/2. Then, we used nested if else condition inside the for loop. If the number is completely divisible by 'i' then, it is not a prime number; else, the number is a prime number. |