C program to find sum of the square of all natural numbers from 1 to N

/*This program will print the sum of the square 
of all natural numbers from 1 to N.*/

#include<stdio.h>
    
int main()
{
	int i,N;
	unsigned long sum;
	
	/*read value of N*/
	printf("Enter the value of N: ");
	scanf("%d",&N);
	
	/*set sum by 0*/
	sum=0;
	
	/*calculate sum of the series*/
	for(i=1;i<=N;i++)
		sum= sum+ (i*i);
	
	/*print the sum*/
	
	printf("Sum of the series is: %ld\n",sum);
	
	return 0;
}

    Enter the value of N: 100
    Sum of the series is: 338350