Test whether a number is prime

Test whether a number is prime

Problem Definition: To verify whether an integer is prime or not.

Problem Analysis: Prime number is an integer which is exactly divisible by 1 and itself.

For example, 17 is a prime number because 1 and 17 are the only two factors of 17.

Generalizing this, a positive integer with just two factors is a prime number.

Examples of prime numbers are 2, 3, 5, 7, 11, 13, ......

To verify whether a number (say) is prime or not, divide the number by 2 to n 1.

If the remainder is zero in any of the cases, then the number is not prime (such numbers are called composite).

Mathematically, it is also enough to divide the number from 2 to √n

Solving by Example: Let us take two numbers 37 and 49.

Consider 37 first. The square root of 37 is 6 (approximately).

Now, divide 37 by 2, 3, 4, 5 and 6.

None of the division operation gives a remainder of zero.

Hence, 37 is a prime number. Now, let us consider 49.

The square root of 49 is 7.So let us divide 49 by 2, 3, 4, 5, 6 and 7.

As 49 is divisible by 7, it is not a prime numbers.

Algorithm Definition

Step 1: Start

Step 2: Read the number n which we want to verify whether prime or not.

Step 3: Initialize the value of the divisor i as.

Step 4: Repeat the following steps till i less than or equal to square root of n. or the remainder of the division operation is zero.

(i) Divide n by i

(ii) if remainders is zero, then prints the number is not prime and exit the process.

Step 5: If none of the remainders are zero, print n is a prime number.

Step 6: Stop

Python : Test whether a number is prime Program List

CCC Online Test 2021 CCC Practice Test Hindi Python Programming Tutorials Best Computer Training Institute in Prayagraj (Allahabad) Best Java Training Institute in Prayagraj (Allahabad) Best Python Training Institute in Prayagraj (Allahabad) O Level NIELIT Study material and Quiz Bank SSC Railway TET UPTET Question Bank career counselling in allahabad Sarkari Naukari Notification Best Website and Software Company in Allahabad Website development Company in Allahabad