➤ If-else Statement in C
➤ Programs on if-else
➤ Switch Case in C
➤ Switch case Programs
➤ Conditional Operator
➤ While loop in C
➤ Do-while loop in C
➤ While vs do-while
➤ For loop in C
➤ Break keyword in C
➤ Continue keyword in C
➤ Break vs Exit in C
➤ Goto keyword in C
☕️ Flow Control Programs
➤ Largest in 3 Numbers
➤ Find Grade of student
➤ Find the absolute value
➤ Vowel or Consonant
➤ Leap Year Program
➤ Simple calculator in C
➤ Check Odd or Even
➤ Roots of Quadratic Equation
➤ Find Reverse of Number
➤ Factors of a number in C
➤ Generate Multiplication table
➤ Find Power of a Number
➤ Find GCD and LCM
➤ Find factorial of Number
➤ Count Number of Digits
➤ Sum of digits in Number
➤ Sum of N Natural Numbers
➤ Sum of Squares of Natural No.
➤ Find Sum of Odd Numbers
➤ Find the Sum of Series
➤ Find Fibonacci series in C
➤ Sum of the Fibonacci series
➤ Sum until enters +ve numbers
➤ Sum of max 10 no. & Skip -ve
☕️ C Conversion Programs
➤ Celsius to Fahrenheit
➤ Fahrenheit to Celsius
➤ Decimal ↔ Binary
➤ Decimal ↔ Octal
➤ Octal ↔ Binary in C
☕️ Number Programs in C
➤ Prime Number in C
➤ Strong Number in C
➤ Krishnamurthy Number
➤ Neon Number in C
➤ Palindrome number
➤ Perfect Number in C
➤ Armstrong Number
☕️ Pattern Programs in C
➤ Pattern programs in C
➤ Printing pattern using loops
➤ Floyd’s triangle Program
➤ Pascal Triangle Program
➤ Pyramid Star Pattern in C
➤ Diamond Pattern Programs
➤ Half Diamond pattern in C
➤ Print Diamond Pattern
➤ Hollow Diamond Pattern
➤ Diamond Pattern of Numbers
In this post, we will write the Perfect number program in C. We will also write a program to check the perfect number in a given range.
Perfect number:- A number whose factors sum, except itself equals the same number.
Example:- 6
Factors of 6 (except itself) are 1,2,3.
The Sum of these factors 1+2+3 = 6 So, 6 is a Perfect number.
Another example:- 28
Factors of 28 (except itself) are 1, 2, 4, 7, 14
The sum of factors of 28 = 1+2+4+7+14 = 28
Hence, 28 is also a perfect number.
The perfect number program is based on finding the factors of a number. If you don’t know how to find factors of a number using the C program then learn it first.
C program to Check Perfect Number
#include<stdio.h>
int main()
{
int num, sum=0;
printf("Enter Number: ");
scanf("%d",&num);
for(int i=1; i<=num/2; i++)
{
if(num%i==0)
sum+=i;
}
if( sum==num )
printf("%d is a perfect number.\n",num);
else
printf("%d is not a perfect number.\n",num);
return 0;
}
Output:-
Enter Number: 6
6 is a perfect number.
Enter Number: 10
10 is not a perfect number.
Enter Number: 28
28 is a perfect number.
The same problem also can be done using while loop.
C program to check Perfect Number in a given Range
#include<stdio.h>
int main()
{
int min, max, sum;
printf("Enter min and max value of the range: ");
scanf("%d %d", &min, &max);
printf("Perfect numbers in the given range are: \n");
for(int i=min; i<=max; i++)
{
sum=0;
for(int j=1; j<=i/2; j++)
{
if(i%j==0)
sum+=j;
}
if(i==sum) printf("%d\t",i);
}
return 0;
}
Output:-
Enter min and max value of the range: 1 100
Perfect numbers in the given range are:
6 28
Enter min and max value of the range: 100 10000
Perfect numbers in the given range are:
496 8128
C program to find the perfect number using the Function
A function is a block of code that performs a specific task. For example, the main is a function and every program execution starts from the main function in C programming.
The function is a small program is used to do a particular task. In C a big program divided into several small subroutines/functions/procedures. Hence C is a function-oriented programming language.
Function to check perfect number
int checkPerfect(int number)
{
int sum = 0;
for(int i=1;i<=number/2;i++)
{
if(number%i==0)
sum += i;
}
if( sum == number ) return 0;
else return 1;
}
Below program checks, the given number is a perfect number or not.
#include<stdio.h>
int checkPerfect(int number)
{
int sum = 0;
for(int i=1;i<=number/2;i++)
{
if(number%i==0)
sum += i;
}
if( sum == number ) return 0;
else return 1;
}
int main()
{
int number, sum=0;
printf("Enter Number: ");
scanf("%d",&number);
if(checkPerfect(number) == 0)
printf("%d is a perfect number.\n",number);
else
printf("%d is not a perfect number.\n",number);
return 0;
}
Output:-
Enter Number: 496
496 is a perfect number.
Enter Number: 500
500 is not a perfect number.
Using the checkPerfect()
function we can also write a C program to find perfect number in a given range, try it yourself.
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