Sira: the Sira has three divisions. There is Mohammed’s life as a prophet and auxiliary material that precedes his prophet-ship and events following his death. The third element is Hisham’s notes. We have a precise word count for Mohammed’s prophet-hood from a scanned version of Guillaume’s The Life of the Muhammad. It covers 579 pages and has a word count of 274,838 words. Since the material from his actual life as a prophet is Sunna, we only use the prophet material.
Total of Koran, Sira (without Sira extras) and Hadith: 1,072,589 words.
As a technical note: if we include the auxiliary material and Hisham, the total word count is estimated to be: 379,700 words.