Ports used by Cpanel Control panel are

2082 cPanel Control Panel
2083 cPanel Control Panel (SSL)
2086 WHM 
2087 WHM (SSL)
2095 Webmail
2096 Webmail (SSL)

It is always better use

http://yourdomain.extn/cpanel
http://yourdomain.extn/whm
http://yourdomain.extn/webmail

As you can get blocked by server firewall if you access wrong PORT. This will be considered as PORT SCAN by many web server security software and auto block your IP.