58.5 million excess electrons are inside a closed surface. what is the net electric flux through the surface?

i know that flux is qinside/e0 (where e0 is a constant). i got -1.058*10^-22, but web assign is saying that's wrong. i know its some simple thing like an orders of magnitude error, but i'm confused on what i'm doing wrong.

The biggest thing you're doing wrong is ignoring the units
when you're working with the quantities.

Now let's look at the rest of the problem:

The formula you used is correct:

           Net flux through the surface = (net charge inside) / ε₀

and          ε₀ = 8.85 x 10⁻¹² farad/meter.

What's the net charge inside the surface in this problem ?

It's    (5.85 x 10⁷ electrons) x (the charge on each electron)

     =  (5.85 x 10⁷ electrons) x (-1.6 x 10⁻¹⁹ coulomb/electron)

     =      -9.36 x 10⁻¹² coulomb .   

Finally,      (net charge inside) / ε₀

             =  (-9.36 x 10⁻¹² coulomb) / (8.85 x 10⁻¹² farad/meter)

             =        -1.058  newton-m²/coulomb .

The sign and the significant figures in your answer are correct, so
we can see that you know what you're doing.  The only thing left is
the order of magnitude.  You most likely took one of the negative
exponents and made it positive.  You got an answer that's 10²² too
small.  Big deal.  You could claim "that's close", and see whether you
can convince a teacher.