You are corect there were 18,000+ B-24s built versue just under 13,000 B-17s assembeled.
The B-17 was al ittle easier to fly than the Lberator but the B-24 had a longer range and bigger payload.
All in all a great 1, 2 punch for the USAAF in WW-II
Regards
alfa6 ;>}