655321

655321 was the prisoner number of Alex, the main character from Stanley Kubrick's film adaptation of A Clockwork Orange. In the original book, by Anthony Burgess, the prisoner number was 6655321.

It may also refer to:
 * The prisoner number of Plankton in the episode "Jailbreak" from the cartoon SpongeBob SquarePants.
 * The prisoner number of Zorak in the episode "Time Machine" in the cartoon The Brak Show.
 * A song on the album We're Already Gone by The Beautiful Girls.
 * The employee number of Nolan Sorrento, a character in the novel Ready Player One.
 * The candidate reference number of Skeletor in The First Purge.
 * A song by Brazilian technopop act Tek Noir.