There are three parts, and the second is divided into two parts, with 512 Questions, 2,669 Articles, and about 10,000 objections and replies. Overall, this monumental accomplishment contains about 1.8 million words, nowadays nearly 6,000 pages of Latin.
I tried to come up with a figure for the number of words I’ve written. My best guess is 200,000 words in 1) publishing (tax law); 2) news and feature stories for a daily; 3) novel, short stories, and true stories; and 4) blog/diary. In addition, as a patrol officer, I wrote hundreds of reports (not published!). Puny amount compared to Thomas.
For more about Aquinas, see https://www.britannica.com/biography/Saint-Thomas-Aquinas/Years-at-the-papal-Curia-and-return-to-Paris