I've been asked to help with a site that another person created. SharePoint 2016, on-premise. Was developed in 2015 and moved to a newer 2016 server. 

While looking at the custom code, I see that the original developer referenced a Content Type ID in a particular function. I have looked at each of the Content Types on the List and none of them match the one in the code.

Just trying to find out what Content Type is associated with the Content Type ID that I have in front of me. 

Can anyone suggest a way to reverse-lookup the content type ID, so I can determine the Content Type it is for?

thanks a bunch!