Semiperfect Number is not Deficient

Theorem

Let $n \in \Z_{>0}$ be a semiperfect number.

Then $n$ is not deficient.

Proof

Let $n$ be semiperfect.

Then by definition, the sum of the aliquot parts of $n$ is not less than $n$.

The result follows by definition of deficient.

$\blacksquare$