Conversation so far:
where is the scrotum located on a male?
The scrotum is a part of the external male genitalia located behind and underneath the penis.
what is the function of the scrotum?
The scrotum has a protective function and acts as a climate control system for the testes.
what causes the wrinkly appearance of the scrotum?
The dartos muscle is found just beneath the skin of the scrotum. It is this layer of tissue that gives the scrotum it's wrinkly look.

Question: how many does a man have?
Self-contained rewrite: how many scrotums does a man have?