"Utilizing an advantage" is not idiomatic, and I have no idea what it would mean to "employ a phone number".   That which is used, employed, or utilized should be a tool, implement, device, or instrument of some kind, something which can be *wielded*, literally or figuratively.


> Let's use this key to see if it works.
>
> We can use her to get to him.


We can *make (good) use* of Google mail's features. We can *put them to use*. We can take advantage of those features.  We can use them to good advantage.