If somebody has social withdrawal and apathy, does he have enough symptoms to have schizophrenia?

Social withdrawal: Not at all. You need to have disorganized thoughts & other psychotic symptoms to say maybe it is schizophrenia or bipolar do.

No: The schizophrenia diagnosis requires much more than apathy and social withdrawal. Usually, people diagnosed with schizophrenia suffer from reality-impairing symptoms such as hallucinations or delusions. In some cases, cognition is severely impaired resulting in very disorganized and illogical thoughts and behaviors.