How many players competed in the deadly games in Squid Game season 1?

How to get close to this number

The number is derived rather than chosen for feel, and the explanation gives the derivation: the prize pool divided by the amount added per death. Working backwards from a stated prize and a stated per-player value gives the participant count exactly, which is unusual for a fictional figure.

That construction is deliberate world-building. A prize that grows with every death makes the survivors complicit in the killing, and tying the participant count to the arithmetic makes the mechanism legible to the audience without exposition. The number is a plot device rather than set dressing.

The protagonist wearing the final number is the detail that confirms the design: the last to register carries the count itself. Fictional numbers are usually round or arbitrary; one that is specific, derivable and assigned to a character is a signal that the writer intended it to be noticed.