Number of divisor

To find the number of divisors of a number, first calculate find by sieve and then try this-

int number_of_divisor(int num)
{
 int j,count,div=1;
 for(j=0;prime[j]<=sqrt(num);j++) //prime array holds the prime numbers
 {
  count=0;
  while(num%prime[j]==0)
  {
   count++;
   num/=prime[j];
  }
  div*=(count+1);
 }
 if(num>1)
  div<<=1;
 return div;
}

This function returns the number of divisors of the given number.