Back to the thing about them asking to confirm a random number, I looked it up a while back when it happened to me. They do it thru google, which gives them your alternate phone number (if you have a google account) and allows them to set up fake phones, fake email accounts etc. for more trolling activities. I think it’s somewhat harmless, but it’s definitely a scam. Shut up Scammer is a perfect response.
I always look up area codes first. If it’s not a fairly local code, I don’t even reply to them.