Postgres.exe on windows format on command line that starts the process

In Windows PostgreSQL spawns numerous postgres.exe processes. When you
look at the actual command line you see the command that started the
process. For example: "c:/PostgreSQL/8.4/bin/postgres.exe" "--forkbackend"
"1372"

My questions
1. In the example above does 1372 represent a port?
2. If it is a port then how can I change the ports used OR avoid using
certain ports?

Thanks,
Bruce.