Multiverse Prime is is the Sub-multiverse where all other Sub-multiverses spawn from.
List of universes
Universe-1: Home universe of the Justice Legion
Universe-2: A universe similar to the Golden Age of Comic Books. Home universe of Justice Squad Infinity
Universe-3: A universe similar to the Antimatter Universe. Home of the Anti-Observer
Universe-4: A universe similar to DC: Earth One. Home universe of Marvelous Man (Universe-4)
Universe-5: The Naked Brothers Band universe
Universe-6: The Supetastic 6 universe
Universe-7: A Kind of Magic universe
Universe-8: Anna Blue's home universe
Universe-9: Monster High universe
Universe-10: The Thief and the Cobbler universe
Universe-11: Interstella 5555 universe
Universe-12: Little Nemo universe
Universe-13: The Modifyers universe
Universe-14: The Secret of Kells universe
Universe-15: Novel Monster High universe
Universe-16: Scott Pilgrim universe
Universe-17: Live-action Scott Pilgrim universe
Universe-18: Comic strip Little Nemo universe
Universe-19:
Universe-20:
Universe-21:
Universe-22:
Universe-23:
Universe-24:
Universe-25:
Universe-26:
Universe-27:
Universe-28:
Universe-29:
Universe-30:
Universe-31: A universe similar to All Star DC Comics.
Slumberland-1: The Version of Slumberland from the movie
Slumberland-2: The version of slumberland from the comic strip
Seventh World: Home universe of Darkone.
Dimension of the Unliving: Home dimension of Nekrotor.
...and many other universes not part of the other Sub-multiverses.