So the Hangouts Dialer app assigns a phone number to your device, which makes it possible to receive calls?
Hangouts dialer lets you assign your Android device to answer calls that are made to your Google Voice telephone number.
Works on Kit Kat and above.
If you do not use your Google Voice number you can still make calls on the Android device but you can’t receive them. And any calls you make display [unknown] as the caller ID.
Getting a Google Voice number is free but local numbers have run out in several large cities... my Voice number is an El Paso number. I used to live there and old friends can make a local call to me and it rings on my Android tablet and smart phone.
You can move your current cellphone number to be your Google Voice number but there is a 20 dollar fee for the paperwork involved. Sometimes that’s the only way to get a local number for Voice though... move your cell number to voice and then get a new cell number.
The really cheap Huawei Ascend Y H866C runs Android 2.3
It’s too old a version to run hangouts Dialer... but there are many other cheap Android phones that can run the app.