Answer
$2\times10^{28}$ electrons. $-3\times10^{9}\;C$.
Work Step by Step
Assume you have a mass of 60 kg (using one significant figure). The mass of a proton plus the mass of a neutron plus the mass of an electron is about $3.34\times10^{-27}\;kg$, so your body contains about $2\times10^{28}$ protons, the same number of neutrons, and the same number of electrons.
The combined charge of the electrons is $-3\times10^{9}\;C$.
