Jamieson, Fausset and Brown on 2 Chronicles 17:14

14. these are the numbers--The warriors were arranged in the army according to their fathers houses. The army of Jehoshaphat, commanded by five great generals and consisting of five unequal divisions, comprised one million one hundred and sixty thousand men, without including those who garrisoned the fortresses. No monarch, since the time of Solomon, equalled Jehoshaphat in the extent of his revenue, in the strength of his fortifications, and in the number of his troops.