An abundant number or excessive number is a number for which the sum of its proper divisors is greater than the number itself.
The integer 12 is the first abundant number. Its proper divisors are 1, 2, 3, 4 and 6 for a total of 16 (> 12).
Derive function abundantNumber(num)/abundant_number(num) which returns true/True/.true. if num is abundant, false/False/.false. if not.