As in a stranger? Doubtful. I know it's not uncommon for people to share numbers with attractive people they just met, but I'd require some good conversation first - conversation that provided info like a name and job and hobbies to prove that we actually have something in common. Attractive (or mesmerizing or captivating) isn't enough for me. Fun question!
There is but one reason to give out your contact information and that is because (you) want to get to know them better. Nevertheless it's always smart to use good commonsense when dealing with strangers. You want to gradually get to know them before giving them total access. Information should be mutually exchanged.
This should be a lot simpler than the world makes it out to be. Sincerity is the code. If you like the person give him the number. You give your contacts to worse people, advertisements, and websites that sell your contacts. Simple, if you like the person do it, he could be someone that will change your life forever. Best wishes