Asking for my phone number while offering hard-to-believe low rent in Manhattan — is this a potential rental scam?

Today, I responded to a couple of Craigslist ads for rentals in the heart of Manhattan, NYC, where I currently live. The rent advertised is about half of what I currently pay, so naturally I am suspicious — perhaps around this time of COVID-19, many scams are designed to take advantage of people struggling for money.

Anyway, I got responses from both ad posters, both of them give a brief "what is your phone number" / "what is your contact number", which seems weird — couldn’t they have just given me their phone number on their email reply to me? They didn’t address me by name, nor did they sign the email reply with theirs.

Here it is, copied and pasted:

Yes…… If interested, please reply with your contact number.

and

Do u have phone number so I’ll send you details. Thanks

If it’s a scam, what can they do with my phone number?

Thanks.