Re: How big is the imager?
It's a marketing ploy. Even if the laws of the physical universe would allow that many pixels on a tiny little sensor, the optics will not resolve that level of detail. To take advantage of a 50-60mp full frame (35mm) sensor, it takes a lens with a whopping great price tag. DXOmark is a good place to look for details on that sort of thing. A serious photographer isn't going to show up on a job with their cell phone and live to book that customer again.
If you need a good camera, the last place you would shop is at the phone store. An adequate camera on your phone is a good enough tool.