I am curious why the need for the external webcam? I can understand the mic, especially if you are recording things farther away and the sound just doesn't pick up well, but the phone should come with its own video capabilities.
That said, yes you can do it, but if you are wanting to use both on a phone, you will need either a smart phone that has both a port and a 3.5mm jack (one for cam and one for mic) or a splitter for the one port. You will also need a OTG Cable for connecting to the port.
Lastly you will need an app that allows for this. There are a few on the Google Play Store.