"23" received generally mixed reviews from music critics, who were ambivalent towards its production and Cyrus' rapping ability. It peaked at number 11 on the U.S. Billboard Hot 100, and charted moderately internationally. An accompanying music video was filmed in Brooklyn on August 26, 2013, and premiered through Vevo on September 24, 2013. It received mixed reviews from critics, who were divided in their opinions of its 1990s and high school influences. Cyrus performed the song during the first leg of her ongoing Bangerz Tour.
During the production of "23", Mike Will Made It prepared a verse for himself to rap, which he originally planned to include alongside verses by Juicy J and Wiz Khalifa. However, after the latter two finished their respective recordings, Mike Will Made It decided that his contribution should be replaced by a woman. Mike Will Made It had recently finished producing Miley Cyrus' track "We Can't Stop" for her fourth studio album Bangerz (2013) when she first heard "23" and expressed interest in being included on the track. Mike Will Made It was initially hesitant of her suggestion, having met her earlier that day, although he "left her on there" after "she laid down the verse [and] killed it."
"23" is a midtempohip hop song, and is distinguished in Cyrus' catalog as the first track in which she raps. In the chorus, Cyrus mentions recreational drug use, particularly in the line "I’m in the club high off purp with some shades on". The track later transitions into the repeated hook "J's on my feet" delivered by Juicy J, which references Air Jordan sneakers. Cyrus' individual verse appears first, and is respectively followed by those by Khalifa and Juicy J.
In addition to its production, music critics were ambivalent towards Cyrus' rapping ability.
Mike Will Made It first previewed a 25-second snippet of "23" on August 7, 2013, and announced that the full recording would be released on August 26; however, its release was eventually delayed. Its original single cover was unveiled by September 3; it features a modified version of Michael Jordan's Chicago Bulls basketball jersey, and was designed by Kreemo of Atlanta, Georgia. The track was ultimately released on September 10, and was serviced to rhythmic contemporary radio stations in the United States on September 17.
"23" received generally mixed reviews from music critics, who were ambivalent towards its production and Cyrus' rapping ability. In a favorable review, Mike Wass of Idolator was complimentary of Mike Will Made It's "slick, multi-layered production" and was indifferent towards Cyrus' contributions. Sharing a similar sentiment, a writer for That Grape Juice stated that the artists "[gave] fans just what they want", adding that they "[went] a long to make the jam the smash that it is."Complex ranked "23" at number 23 on their list of the 50 best songs of 2013, saying that Mike Will Made It knew that Miley would make this collaboration even better. However, in a more mixed review, Danielle Cheesman of MSN opined that "the song sounds like everything else Mike WiLL's touched and turned to gold so it will be a smash but, much to Miley's chagrin, it won't be because of her", and criticized Cyrus' verses for "[stealing 2 Chainz's] whole flow." Tony Maglio from The Wrap also questioned her lyrical content, specifically criticizing the lyrics "I back it up, cause I don’t give a fuck" and "I’m MC Hammer fly." Jordan Sargent from Spin called the track "far from Mike Will's best work" and negatively compared Cyrus' delivery to that of Lil Debbie.
An accompanying music video for "23" was filmed in an undisclosed location in Brooklyn on August 26, 2013; it was directed by Hannah Lux-Davis. An advertisement for a casting call posted to Juicy J's Instagram account requested "edgy, rebellious, sexy, [and] hood types" to appear as extras in the clip, and further stated that individuals "must wear [their] favorite pair of Jordans".
The music video was premiered through Vevo on September 24. The music video takes place in a high school; it begins with the school principal leaving his office, which Mike Will Made It enters and begins playing "23" on a Beats Pill over the intercom. Interspersed throughout are scenes of Cyrus wearing a bikini similar to Michael Jordan's Chicago Bulls basketball jersey; she is frequently shown smoking in the bathroom and writing on its mirrors with red lipstick. Khalifa raps his verse in a chemistry lab, while Juicy J's verse is rapped in a trophy room. A school-wide pep rally later takes place, where Cyrus is notably wearing the foam finger used in her controversial performance at the 2013 MTV Video Music Awards in August.
Critics were divided in their opinions for the music video. In a more favorable review, Zayda Rivera of Daily News stated that Cyrus is "undoubtedly the star of the video" and that the "ultimate cameo takes place when Cyrus brings back the infamous foam finger she waved and gyrated against during her MTV Video Music Awards performance". Ray Rahman from Entertainment Weekly recognized the prominent 1990s influence throughout the clip, and felt it was "reminiscent" to the visuals for "Make 'Em Say Uhh!" by Master P. In a more critical review, Carl Williott of Idolator opined that the music video was "sort of like a massive hip-hop version of the "Smells Like Teen Spirit" video, with Air Jordans and Beats instead of anarchy symbols", while Kayla Upadhyaya from The Michigan Daily called it a "pile of red and black vomit and a poorly edited mishmash of uninspired shots".
Cyrus performed the song during the first leg of her ongoing Bangerz Tour. During the second leg of the tour, "23" was replaced with Lucy in the Sky with Diamonds. During the performance, Cyrus wore black-and-red Jordan 1s, a striped fishnet bikini and crotchless leather chaps with "Miley" scrawled down the side, through which she paid homage to Christina Aguilera's "Dirrty" music video. Aguilera herself approved of the outfit and named Cyrus her dirrty girl successor, writing, "Cheers from one dirrty girl to the next @MileyCyrus...wear em' loud & proud, girl- yes!!" on her Twitter account. Jane Stevenson of the Toronto Sun praised the performance and wrote that it saw Cyrus finally twerk it out with her dancers.