Frantic Canadian said:
We didn't get #53000 but we did break that barrier.
At some point in the near future, there will be a film #53,000. The film numbers are not usually issued in sequence as the weekly bulletin is released every week. We made it into that milestone, though.
I discovered several numbers:
121 Alibi Bye Bye (short)
11346 Oh, Professor Behave! (short)
13141-13155 Congo Bill (serial)
13601-13615 Bruce Gentry (serial)
13771-13785 Adventures of Sir Galahad (serial)
14141 So You Think You're Not Guilty (short)
14143 The Grass Is Always Greener (short)
14144 My Country 'Tis of Thee (short)
14157* The Wearing of the Grin (short)
*in film, no number, just logo but verified by a researcher on an archived website
14361-14375 Atom Man vs. Superman (serial)
14471 A Wife's Life (short)
14551-14565 Pirates of the High Seas (serial)
14720 I Love Children But... (short)
14884 Night Without Stars (instead of 15589 which is surely incorrect)
15103 One Wild Night (short)
15581-15595 King of the Congo (short)
15721-15735 Blackhawk (serial)
15911-15925 Son of Geronimo (serial)
16251-16265 The Lost Planet (serial)
16421-16435 The Great Adventures of Captain Kidd (serial)
16721-16735 Gunfighters of the Northwest (serial)
16798 Arrow in the Dust
17001-17015 Riding with Buffalo Bill (serial)
17231-17245 The Adventures of Captain Africa (serial)
17481 The Nat 'King' Cole Musical Story (short)
17551-17565 Perils of the Wilderness (serial)
17799 So You Want to Play the Piano (short)
17801-17815 Blazing the Overland Trail (last serial ever)
21354 Thunderbirds Are Go
21585* Congratulations It's Pink (short)
*Instead of 21545 which was taken by The Music Mice-Tro, a Looney Tunes short. The number is guessed to fit the sequence of five DePatie-Freleng shorts (21583-21587).
21594 In Enemy Country
21595 Madigan
21798 The Legend of Custer