It's about 110 billion, i.e., about 1/10 of a trillion. This estimate isn't sensitive to when you start counting (i.e., from what time do you consider our ancestors to be human) since populations were very low then compared to recent populations.
For the Population Reference Bureau estimate, and how the current population and the "ever lived" population have changed over time, see https://www.prb.org/howmanypeoplehaveeverlivedonearth/
This point came up in a recent question about whether the living outnumber the dead
which might be of interest.