It is a best practice to always use a consistent port number when creating SharePoint Central Administration sites. This is so that no matter which server or environment you are on, all you need to know is the name of the server, and since the port number is always the same, it's easy to remember the URL.
I like to use 9999 as the port number. So the URL for your Central Admin site would be:
If your Central Admin sites have already been configured with a different port number, you can easily change them by running a simple PowerShell command:
Set-SPCentralAdministration -Port <portnumber>
Where <portnumber> is the port number that you want to use. In my case it would be "9999."