Hundreds.
Digital or print? Both Had some printed for my partner, now husband. And there are some life sized photographs as artwork (purchased by artists' clients)
Who took them? Lots of people. When I was figure modeling, some of the atelier students took some, but more of them were taken by professional artists, photographers and sculptors. I was photographed many times in public venues (Folsom, Folsom East & Dore Alley) My producer took many of them for approval by the guys I was to play with in video. The earliest one, the one I was most embarrassed by, was taken by my mother when I was in a bathtub with my two older brothers (at age 4). I thought my dick was too big compared to my brothers'....
Where are they stored? Some digital ones are on my, and others' computers. One sculptor (my former neighbor) put mine all over the walls of her home studio, and her 21 year old daughter became fascinated with them, and me.
Are any in your phone? No - keep them off there.