The two Italian internationals grew up together, went to the same school and played in the same Inter team.
Santon told the Sunday Mirror: "Balotelli was with me, not just in football at Inter Milan, but in school. I am a year younger than him, but we were good friends.
"He's a funny boy, if a little bit crazy. I keep in touch with him.
"We speak sometimes and send each other texts. Mario is a tremendous footballer. He's not a bad guy, just crazy!"