How many hearts does a human body have?

No.

Actually humans can have 2 hearts.

A few years back in Canada; a boy was born with 2 beating hearts, as seen in sonogram. But when born, the right heart stopped beating. Doctors our not sure, but they find it possible for the right heart too start beating when the left one dies out. they boy also posseses a much higher amount of cells than an average human and a high healing factor.

hope this helps.