Perfect+Perfect=Perfect ?

Let $N_1$ and $N_2$ are two perfect numbers greater than $6$

When consider modulo $6$ implies we consider modulo $2$ and $3$ Obviously modulo $2$ gives $0$ . And with $p$ as odd, modulo $3$ gives $(-1)^{\text{even}} \times ( (-1)^{\text{odd}} - 1 ) \equiv 1$ . Which gives $4$ modulo $6$ .

So $N_1 \equiv 4\pmod 6$ and $N_2 \equiv 4\pmod 6$

Thus $N_1+N_2 \equiv 2\pmod 6$ .

Thus $N_1+N_2$ is not perfect.

So the answer is $\boxed{0}$