# Input number and check perfect number or not using while loop in Python

###### while Loop - Question 8

In this question, we will see how to input a number and check if it is a perfect number or not in Python programming using while loop. To know more about while loop click on the while loop lesson.

**Q8)** Write a program in Python to input a number and check if it is a perfect number or not using while loop.

A Perfect number is a number, whose sum of the factors excluding the given number itself is equal to the given number.

Example: Sum of factors of 6 excluding 6 is 1+2+3 which is equal to 6, so 6 is a perfect number.

#### Program

```
i=1; sf=0
n=int(input('Enter a number '))
while i<n:
if n%i==0:
sf=sf+i # sum of factors
i=i+1
if sf==n:
print('Perfect Number')
else:
print('Not Perfect Number')
```

#### Output

Enter a number 28 Perfect Number