well the stance is "rooish," so I'm going to guess a rooster. It would be better is you had close ups of the front of his head so we can see the comb he has.
! Pleased you joined our community! Sorry - I know nothing about Sultans...you might hunt down the Sultan thread in the link below and post the pic there...or...post the pic in the second link. Drumstick is right, though...a closer pic of the head would be useful. Good luck to you!
Definitely a roo. I raised one from a chick and thought he was a "she" which is why i named him "Sally"....the name stuck but he started developing a comb and wattles like yours and now he is a handsome full grown man