STRONG NUMBER in c programming language

void main()

{

int num,i,f,r,sum=0,temp;

clrscr();

printf("\nEnter a number");

scanf("%d",&num);

temp=num;

while(num)

{

i=1,f=1;

r=num%10;

while(i<=r)

{

f=f*i;

i++;

}

sum=sum+f;

num=num/10;

}

if(sum==temp)

printf("%d is a strong number",temp);

else

printf("%d is not a strong number",temp);

getch();

}