Hojat-ol-Islam Ali Mohammadi made the remark in an interview with the Quran TV on Friday, hoping that the number will rise to 5 million in the future.
He said until a few years ago there were only some 250,000 contenders in Quran competitions but this year the number rose to over a million.
During the interview, Hojat-ol-Islam Ali Mohammadi also elaborated on the activities of the Awqaf and Charity Affairs Organization.
He said the organization has made extensive efforts to train memorizers of the Holy Quran and that 300,000 people have registered to take part in the second phase of the Quran memorization training plan.