Can iPhone be hacked via text messaging?

Can your iPhone 5s be hacked or compromised in any way if you share your cell number with someone and they text you remotely? That is, they have no physical access to your phone. All they know is your number. I've read they can call you and you don't even have to pick up and you can get hacked. Is this true??? If so, what can I do to recover from this incident?