Program to determine whether a given number is a Deficient number

The deficient number can be defined as the number for which the sum of the proper divisors is lesser than the number itself.

For example, the number 21 with its proper divisors (1, 3 and 7) has sum (11) lesser than itself.

Algorithm

MAIN

• STEP 1: START
• STEP2: Enter n
• STEP 3: if Def(n) is true then
  print "yes"
  else
  print "no"
• STEP 4: END

Def(n)

• STEP 1: START
• STEP 2: set i = divsum(n)
• STEP 3: if i <2n
  then return true
  else
  return false
• STEP 3: END

divsum(n)

• STEP 1: START
• STEP 2: SET sum= 0
• STEP 3: REPEAT STEP 4 UNTIL i<=?n
• STEP 4: if (n% i==0)
  then
  if(n/i==i)
  sum=sum+i
  else
  sum=sum+i
  sum=sum+ (n/i)
• STEP 5: RETURN sum
• STEP 6: END

Java Program

Output:

Enter the number? 23
The number is deficient.

C Program

Output:

Enter the number? 21
The number is deficient.

Python Program

Output:

Enter the number? 45
The number is deficient.

C# Program

Output:

Enter the number? 45
The number is deficient.

PHP Program

Output:

Enter the number? 45
The number is deficient.