1. PERFECT NUMBER.
void main()
{ int n,i=1,sum=0;
clrscr();
printf("\nEnter a number:-");
scanf("%d",&n);
while(i <n)> {
if(n%i==0)
sum=sum+i;
i++;
}
if(sum==n)
printf("\nThe no %d is a perfect number",i);
else
printf("\nThe no %d is not a perfect number",i);
getch();
}
2. ARMSTRONG NUMBER.void main()
{
int num,r,sum=0,temp;
clrscr();
printf("\nEnter a number:-");
scanf("%d",&num);
temp=num;
while(num!=0)
{
r=num%10;
num=num/10;
sum=sum+(r*r*r);
}
if(sum==temp)
printf("\nThe number %d is an armstrong number",temp);
else
printf("\nThe number %d is not an armstrong number",temp);
getch();
3. Prime Number.
void main()
{
int num,i,count=0;
clrscr();
printf("\nEnter a number:");
scanf("%d",&num);
for(i=1;i<=num;i++) { if(num%i==0) count++; } if(count==2) printf("%d is a prime number",num); else printf("%d is not a prime number",num); getch(); }
4. Fibonacci Number.
void main()
{
int i=0,j=1,k=2,r,f;
clrscr();
printf("Enter the number range:");
scanf("%d",&r);
printf("\nFIBONACCI SERIES: ");
printf("%d %d",i,j);
while(k<r)
{
f=i+j;
i=j;
j=f;
printf(" %d",j);
k++;
}
getch();
}
