Primitive Semiperfect Number/Examples/28

Example of Primitive Semiperfect Number
$28$ is a primitive semiperfect number:
 * $1 + 2 + 4 + 7 + 14 = 28$

Proof
We have that $28$ is a perfect number:
 * $28 = 1 + 2 + 4 + 7 + 14$

The result follows from Perfect Number is Primitive Semiperfect.