# Armstrong Number in C

July 07, 2021

Before going to the Amstrong number in C, Let's understand how to check a number is Armstrong or not.

If a number is equal to the sum of cubes of its digits, then the number is the Amstrong number. 0, 1, 153, 370 .. are Amstrong numbers.

Let's understand how to check 370 is an Amstrong Number:

370 = (3*3*3+7*7*7 +0*0*0)

= 370

Hence 370 is an Amstrong Number

To understand this program, You should have knowledge of

• C If else Statement
• C While loop

Program to check Armstrong number in c

```    #include
int main()
{
int num,rem,sum=0,temp;
printf("Enter a number: ");
scanf("%d",&num);
temp=num;
while(num>0){
rem=num%10;
sum=sum+(rem*rem*rem);
num=num/10;
}
if(temp==sum){
printf("Armstrong Number");
}else{
printf("Input Number is not an Armstrong Number");
}
return 0;
}
```

Output

Enter a number: 370
Input Number is not an Armstrong Number

0 0
July 07, 2021
```    #include <stdio.h>

int main() {
int temp, rem, sum = 0;
int armstrong_number = 370;

temp = armstrong_number;

while(temp != 0) {
rem = temp % 10;
sum = sum + (rem * rem * rem);
temp = temp / 10;
}

if(sum == armstrong_number)
printf("%d is an Armstrong number.", armstrong_number);
else
printf("%d is not an Armstrong number.", armstrong_number);

return 0;
}
```

Output

370 is an Armstrong number.

0 0
July 08, 2021

C program to check Amstrong Number using User Defined Function

```    #include <stdio.h>

int checkIsAmstrogNo(int number)
{
int temp=number;
int rem,sum;

sum=0;
while(temp!=0)
{
rem=temp%10;
sum=sum + (rem*rem*rem);
temp=temp/10;
}

if(sum==number)
return 1;   //Amstrong Number
else
return 0;   //Not an Amstrong Number
}

int main()
{
int num;

printf("Enter an integer number: ");
scanf("%d", &num);

if(checkIsAmstrogNo(num))
printf("%d is an Armstrong number.",num);
else
printf("%d is not an Armstrong number.",num);

return 0;
}
```

Output:

Enter an integer number: 370
370 is an Armstrong number.

0 0
October 17, 2022

Let us check What is an Amstrong Number. If the sum of cubes of its digits is equal to its number, then the number will be an Amstrong number.

Eg:

Let's check why 153 is an Armstrong number.

153 = (1*1*1)+(5*5*5)+(3*3*3) = 153

The sum of cubes of its digits is equal to the number.

```    #include
int main()
{
int num,rem,sum=0,temp;
printf("Enter the number=");
scanf("%d",&num);
temp = num;
while(num>0)
{
rem = num%10;
sum = sum+(rem*rem*rem);
num = num/10;
}
if(temp == sum){
printf("Amstrong Number");
}else{
printf("Not an Amstrong Number");
}
}
```

Output

Enter the number=153
Amstrong Number

0 0