I was trying to find an answer to this question, and came across this page:
The Guinness Book of Records of 1985 has this entry:
Human memory: Bhandanta Vicitsara (sic) recited 16000 pages of Buddhist cannocial texts in Rangoon, Burma in May 1954. Rare instances of eidetic memory the ability to project and hence “usually” recall material are known to science.
(I don’t think there is any photographic memory known to science.)
It mentions 2.4 million words:
It is an oral and written examination lasting thirty-three days. The candidate is examined in the three Pitakas: Vinaya, Sutta and Abhidhamma. The oral examination in the Vinaya covers five volumes in five books comprising 2260 pages. In the Sutta, the oral examination covers three volumes in the three books comprising 782 pages and in Abhidhamma covers seven volumes in twelve books comprising 4941 pages. The oral examination on these 7983 pages or about 2.4 million words is not a viva voce, a question and answer examination. It is an examination on total recall and faultless reproduction. The candidate will be given a point in the Pali Cannon at any point, and asked to continue reciting from there, line by line, paragraph and page by page. Or he would be given a point and asked to go back from there a certain number of sections and to recite from there, There must be no error in the word form, the pronunciation must be correct, the flow must be smooth and the enunciation must demonstrate the proper understanding of the meaning of the passage being recited. A certain number of pages of text must be covered in a fixed time. A candidate who requires prompting for five or more times fails.
Here’s his Wikipedia page.
If anyone knows more about that feat, leave a comment below. 