Deuteronomy is 27,682 words. At an average adult reading pace of 300 words a minute that is about 1 hr 32 min, or roughly 1 hr 9 min if you read quickly and 2 hr 18 min at a more deliberate 200 words a minute.
That count is measured from the complete public-domain text rather than estimated from a page count, so you can compare all the books side by side.