I asked a somewhat related question in May 2015: What needs to be different in order for a parthenogenetically reproducing species to evolve sentience?
The answers might be useful to you, although they focus on the conditions in which asexual reproduction might dominate rather than on what the mechanics would be. As BlindKungFuMaster has said above there is no obvious reason why the humanoid shape, or sentience, should be a barrier to it occurring. It is rare but not unknown in large animals. It sometimes occurs in komodo dragons and turkeys.
Note that parthenogenesis can occur with or without mitosis, though I confess I don't really understand what "Parthenogenesis can occur without meiosis through mitotic oogenesis" means.
