Are headphones with these numbers good quality?

Numbers mean nothing.

Here's a quick overview of what's good and what's not in the headphone world...

Bad (Don't Buy)

Skullcandy

Beats by Dre

Bose

Good (Do Buy)

Shure

Sennheiser

AKG

Grado

Denon

Audio Technica

KRK

Ultrasone

Etymotic

Beyerdynamic

Sony

Numbers do not tell what the sound quality will be, they do not tell what the build quality of the headphones will be, they don't really tell anything about the headphones.

All they tell you is whether or not you will need a headphone amplifier and what the range of the drivers would be. Those could be awesome headphones, or they could be terrible headphones... you need to give a brand and model number for anyone to tell.

Yeah.. but you don't represent the company