President Kovind was addressing the 66th convocation ceremony of the Gujarat University (GU) in Ahmedabad.
"Kalam sir was ultimately and fortunately my predecessor. Though he became the president, he was basically a scientist. Thus, I usually refer to him as a 'space scientist' while I call Modiji a 'social scientist'," President Kovind said in his address.
"While Modiji was an alumnus of the Gujarat University, Kalam sir too had stayed here for some time," he said.
On a lighter note, the President said that none of the students present at the ceremony would have sold tea like PM Modi did in his younger days.
He said that PM Modi opened the doors of the 21st century for today's generation by bringing in various initiatives, such as 'Digital India' and 'Start Up India'.
President Kovind urged students to keep in mind the ethos of cooperation and brotherhood to bring in development.
As many as 56,159 graduates of the GU, the oldest varsity of the state, were awarded degrees at the convocation ceremony.