# Python Program to Check Prime Number

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## What is Prime Number?

A positive integer that is divisible only by itself and 1.

Tips: It is recommended to use our online Prime Numbers calculator for better understanding.

## Examples

The following table provides few examples of prime numbers.

NumberDivisorResult
13 1, 13 Prime Number
15 1, 3, 5, 15 Not a Prime Number
47 1, 47 Prime Number

## Using for loop

In the following example, we will check whether the given number (7) is a Prime number or not using for loop.

### Example

Python Compiler
num = 7 count = 0 for i in range(1, num+1): if(num % i == 0): count += 1 if(count == 2): print("%d is a prime number" % num) else: print("%d is a NOT prime number" % num)

## Using while loop

In the following example, we will check whether the given number (7) is a Prime number or not using while loop.

### Example

Python Compiler
num = 7 i = 1 count = 0 while(num >= i): if(num % i == 0): count += 1 i += 1 if(count == 2): print("%d is a prime number" % num) else: print("%d is a NOT prime number" % num)

## Prime Numbers between the Given Range

In the following example, we will find all the Prime numbers between 1 and 20.

### Example

Python Compiler
start = 1; end = 20; print("Prime numbers between 1 and 20:") for start in range(start, end+1): count = 0; for i in range(1, start+1): if(start % i == 0): count += 1 if(count == 2): print(start, end=" ")

## Check Whether the Given Number is Prime or Composite

In the following example, we will check whether the given number is a Prime number or Composite number.

### Example

Python Compiler
num = int(input("Enter a (int) number: ")); count = 0; for i in range(1, num+1): if(num % i == 0): count += 1; if(count > 2): print("%d is a composite number" % num) else: print("%d is a prime number" % num)