Can anybody hack a smartphone (android or iPhone) knowing just his mobile number ?

Hi guys, A couple of days ago I stupidly contacted a guy via WhatsApp, just a few seconds and I understood it was a fake account and I made a mistake, so I blocked and reported it. But I have now exposed my number. My question is, can anybody bypass my 2 factor authentication with app+sms pin code, just hacking my phone knowing just my number ?