Can't listen on port 80 with my server

Very new on this kind of issue, i am trying to launch a server on the port 80 (it's important to me to use this specific port).

It's fails, but it works on other ports (even < 1024 when i am root, but still fail on the port 80).

I probably have something running on the port 80, i would like to identify it in order to change its listening port.

I saw this cmd can help to see the state of a specific port: netstat -ano|grep 80|grep LISTEN but i am not sure tu understand well the result.

Here is what i get:

tcp        0      0 127.0.0.1:28017         0.0.0.0:*               LISTEN      off (0.00/0/0)tcp6       0      0 :::80                   :::*                    LISTEN      off (0.00/0/0)unix  2      [ ACC ]     STREAM     LISTENING     8805     /tmp/mongodb-27017.sockunix  2      [ ACC ]     STREAM     LISTENING     13112    /home/me/.pulse/04d802bb34ddb9da49b1f9060000000b-runtime/native

I read on the line 2 that the port 80 seems to be not listening, but don't understand further.

UPDATE:

sudo lsof -i :80

COMMAND    PID     USER   FD   TYPE DEVICE SIZE/OFF NODE NAMEapache2   1107     root    4u  IPv6   7630      0t0  TCP *:http (LISTEN)apache2   1131 www-data    4u  IPv6   7630      0t0  TCP *:http (LISTEN)apache2   1132 www-data    4u  IPv6   7630      0t0  TCP *:http (LISTEN)apache2   1133 www-data    4u  IPv6   7630      0t0  TCP *:http (LISTEN)apache2   1134 www-data    4u  IPv6   7630      0t0  TCP *:http (LISTEN)apache2   1136 www-data    4u  IPv6   7630      0t0  TCP *:http (LISTEN)ubuntu-ge 2095     me    7u  IPv4  82145      0t0  TCP me-Ubuntu.local:43345->mulberry.canonical.com:http (CLOSE_WAIT)

Thanks (i am using ubuntu) !