5 (number)

5 was a prime number. (AUDIO: The Haunting)

In November 1963, Susan Foreman said that the last five months had been the happiest of her life (indicating that was how long she had been living in England). (TV: "An Unearthly Child") In March of that year, Susan wrote in her journal that they'd been in 1963 for five months, or at least it seemed like it. (PROSE: Time and Relative)

Upon meeting the Fifth Doctor, the First Doctor exclaimed "goodness me!" as he realised that he now had five incarnations. Elsewhere, an illusionary Liz Shaw told the Third Doctor that there were now five of him, to which he exclaimed "oh, good grief." (TV: The Five Doctors)

In early 2005, A. Fergus was doing a report on the fifth birthday of the London Eye for 60 Seconds on BBC3, when the Ninth Doctor, with blood on his face, told Fergus and his crew to run, and despite them being hardened professionals, they ran like children, not stopping to ask questions. Fergus later wrote about his encounter on whoisdoctorwho.co.uk. (PROSE: Have You Seen This Man?)

A sign in London on 25 December 2006 featured the number "5". (TV: The Christmas Invasion)

The countdown towards the Ninth Doctor's eviction on Big Brother counted from 6 to 0, going through 5, 4, 3, 2, and 1. (TV: Bad Wolf)In an emergency transmission sent by the TARDIS, the Thirteenth Doctor listed 5 things that she did in any worrying situation. The fifth was staying strong and staying positive. (WC: Message from the Doctor)