Adele's album 21 spent 24 weeks at number one on the Billboard 200.
Released in the United States on 22 February 2011, 21 became a remarkable sleeper hit. It debuted at number one with first-week sales of 352,000 copies, then continued attracting listeners through radio hits such as “Rolling in the Deep,” “Someone Like You,” and “Set Fire to the Rain.”
Its 24-week run at the top was the longest for any album since 1985 at the time and the longest for a female solo artist in Billboard 200 history. The album also remained in the top 10 for 84 weeks, showing that its success was much broader than a brief chart surge.
The title refers to Adele's age when she began writing the album. It is often confused with 25 or 30, the titles of her later albums. 21 became a major commercial and cultural milestone, eventually earning Diamond certification in the United States for sales exceeding 10 million copies.