// C++ program to implement an Optimized Solution // to check Deficient Number #include    using namespace std; // Function to calculate sum of divisors int divisorsSum(int n) {  int sum = 0; // Initialize sum of prime factors  // Note that this loop runs till square root of n  for (int i = 1; i <= sqrt(n); i++) {  if (n % i == 0) {  // If divisors are equal take only one  // of them  if (n / i == i) {  sum = sum + i;  }  else // Otherwise take both  {  sum = sum + i;  sum = sum + (n / i);  }  }  }  return sum; } // Function to check Deficient Number bool isDeficient(int n) {  // Check if sum(n) < 2 * n  return (divisorsSum(n) < (2 * n)); } /* Driver program to test above function */ int main() {  isDeficient(12) ? cout << 'YESn' : cout << 'NOn';  isDeficient(15) ? cout << 'YESn' : cout << 'NOn';  return 0; } 

// Java program to check Deficient Number import java.io.*; class GFG {  // Function to calculate sum of divisors  static int divisorsSum(int n)  {  int sum = 0; // Initialize sum of prime factors  // Note that this loop runs till square root of n  for (int i = 1; i <= (Math.sqrt(n)); i++) {  if (n % i == 0) {  // If divisors are equal take only one  // of them  if (n / i == i) {  sum = sum + i;  }  else // Otherwise take both  {  sum = sum + i;  sum = sum + (n / i);  }  }  }  return sum;  }  // Function to check Deficient Number  static boolean isDeficient(int n)  {  // Check if sum(n) < 2 * n  return (divisorsSum(n) < (2 * n));  }  /* Driver program to test above function */  public static void main(String args[])  {  if (isDeficient(12))  System.out.println('YES');  else  System.out.println('NO');  if (isDeficient(15))  System.out.println('YES');  else  System.out.println('NO');  } } // This code is contributed by Nikita Tiwari 

# Python program to implement an Optimized  # Solution to check Deficient Number import math # Function to calculate sum of divisors def divisorsSum(n) : sum = 0 # Initialize sum of prime factors # Note that this loop runs till square # root of n i = 1 while i<= math.sqrt(n) : if (n % i == 0) : # If divisors are equal take only one # of them if (n // i == i) : sum = sum + i else : # Otherwise take both sum = sum + i; sum = sum + (n // i) i = i + 1 return sum # Function to check Deficient Number def isDeficient(n) : # Check if sum(n) < 2 * n return (divisorsSum(n) < (2 * n)) # Driver program to test above function  if ( isDeficient(12) ): print ('YES') else : print ('NO') if ( isDeficient(15) ) : print ('YES') else : print ('NO') # This Code is contributed by Nikita Tiwari 

// C# program to implement an Optimized Solution // to check Deficient Number using System; class GFG {  // Function to calculate sum of  // divisors  static int divisorsSum(int n)  {  // Initialize sum of prime factors  int sum = 0;  // Note that this loop runs till  // square root of n  for (int i = 1; i <= (Math.Sqrt(n)); i++) {  if (n % i == 0) {  // If divisors are equal  // take only one of them  if (n / i == i) {  sum = sum + i;  }  else // Otherwise take both  {  sum = sum + i;  sum = sum + (n / i);  }  }  }  return sum;  }  // Function to check Deficient Number  static bool isDeficient(int n)  {  // Check if sum(n) < 2 * n  return (divisorsSum(n) < (2 * n));  }  /* Driver program to test above function */  public static void Main()  {  string var = isDeficient(12) ? 'YES' : 'NO';  Console.WriteLine(var);  string var1 = isDeficient(15) ? 'YES' : 'NO';  Console.WriteLine(var1);  } } // This code is contributed by vt_m 

 // PHP program to implement  // an Optimized Solution // to check Deficient Number // Function to calculate // sum of divisors function divisorsSum($n) { // Initialize sum of // prime factors $sum = 0; // Note that this loop runs  // till square root of n for ($i = 1; $i <= sqrt($n); $i++) { if ($n % $i==0) { // If divisors are equal  // take only one of them if ($n / $i == $i) { $sum = $sum + $i; } // Otherwise take both else { $sum = $sum + $i; $sum = $sum + ($n / $i); } } } return $sum; } // Function to check // Deficient Number function isDeficient($n) { // Check if sum(n) < 2 * n return (divisorsSum($n) < (2 * $n)); } // Driver Code $ds = isDeficient(12) ? 'YESn' : 'NOn'; echo($ds); $ds = isDeficient(15) ? 'YESn' : 'NOn'; echo($ds); // This code is contributed by ajit;. ?> 

<script> // Javascript program to check Deficient Number  // Function to calculate sum of divisors  function divisorsSum(n)  {  let sum = 0; // Initialize sum of prime factors    // Note that this loop runs till square root of n  for (let i = 1; i <= (Math.sqrt(n)); i++)  {  if (n % i == 0)   {    // If divisors are equal take only one  // of them  if (n / i == i) {  sum = sum + i;  }  else // Otherwise take both  {  sum = sum + i;  sum = sum + (n / i);  }  }  }    return sum;  }    // Function to check Deficient Number  function isDeficient(n)  {    // Check if sum(n) < 2 * n  return (divisorsSum(n) < (2 * n));  } // Driver code to test above methods  if (isDeficient(12))  document.write('YES' + '  
');  else  document.write('NO' + '  
');    if (isDeficient(15))  document.write('YES' + '  
');  else  document.write('NO' + '  
');    // This code is contributed by avijitmondal1998. </script>