The Doctor's lucky number

Among their various incarnations, the Doctor considered several numbers to be their lucky number.

After being condemned to death by the seventh holy ritual of the Great Book, the Fourth Doctor told Ranquin that 7 was his lucky number. (TV: The Power of Kroll) When told by Romana II that their chances of survival were 74384338 to one against, the Doctor gave the former as his lucky number, remarking that the coincidence was extraordinary. (TV: The Creature from the Pit)

The Ninth Doctor considered 9 to be his lucky number. (AUDIO: The Other Side)

The Twelfth Doctor perhaps jokingly told Bors that 12 was his lucky number after Bors and his men had tried digging in eleven different spots that were all rejected by the Doctor in an attempt to build a well. (TV: The Doctor's Meditation) When discussing superstition, the Doctor remarked that his lucky number was technically seven doubled due to his regenerations, before calling himself the king of good luck. (COMIC: Witch Hunt)