Program 1

#include<stdio.h>
int main() {
	int num,i,f,r,sum=0,temp;
	printf("Enter 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);
	return 0;
}

Result

Enter a number: 145
145 is a strong number

Program 2

#include<stdio.h>
int main() {
	int num,i,f,r,sum,temp;
	int min,max;
	printf("Enter minimum range: ");
	scanf("%d",&min);
	printf("Enter maximum range: ");
	scanf("%d",&max);
	printf("Strong numbers in given range are: ");
	for (num=min; num <= max; num++) {
		temp = num;
		sum=0;
		while(temp) {
			i=1;
			f=1;
			r=temp%10;
			while(i<=r) {
				f=f*i;
				i++;
			}
			sum=sum+f;
			temp=temp/10;
		}
		if(sum==num)
		           printf("%d ",num);
	}
	return 0;
}

Result

Enter minimum range: 100
Enter maximum range: 100000
Strong numbers in given range are: 145 40585