Stellaris 4.5.2 origins
Stellaris 4.5.2 has 62 origins players can pick (48 of them need a DLC) and 15 more the game gives to other empires. An empire picks one origin at creation; it cannot be changed later.
Origins players can pick
Origins only the game uses
Fallen empires, primitives, released vassals and other countries the game creates.
Origins: questions
How many origins are in Stellaris 4.5.2?
62 that players can pick, and 15 the game keeps for other empires (common/governments/civics, is_origin = yes).
Can you change your origin in Stellaris?
No. An origin is picked when the empire is created; it is not a civic slot.
Source: common/governments/civics (is_origin = yes) and gfx/event_pictures/origins, Stellaris Cygnus v4.5.2 (9776).