Just use the basic definition of "abundant" and "deficient". That is, calculate all the factors of 50 (excluding 50 itself), add them up, then compare whether the result is more or less than 50.
prfct nmbr
abundant
deficient
It is deficient.
abundant
it is abundant
deficient
It is deficient.
13 is deficient.
perfect
36 is abundant.
It's deficient