js perfect number
[ASSIGNMENT]:

  Perfect number
In number theory, a perfect number is a 
positive integer that is equal to the sum 
of its proper positive divisors, that is, 
the sum of its positive divisors "excluding 
the number itself".
Equivalently, a perfect number is a number 
that is half the sum of all of its positive 
divisors (including itself).


 For example:
 
The first perfect number is 6. Its proper 
divisors are 1, 2, and 3, and 1 + 2 + 3 = 6. 

Equivalently, the number 6 is equal to half 
the sum of all its positive divisors: 

    ( 1 + 2 + 3 + 6 ) / 2 = 6. 

The next perfect number is 28.

    28 = 1 + 2 + 4 + 7 + 14. 

This is followed by the perfect numbers 496 
and 8128.

 Read more: Perfect_number

You are requested to write a function that 
returns true "boolean value" if the number 
is perfect or false "boolean value" if not 
or if number is negative.
perfect_number js
