Lakers forward LeBron James intended to give his No. 23 to Davis, who was acquired from the Pelicans last month, but the deadline to change numbers had passed. Nike shot down an exception to get the number changed so James will wear No. 23 next season.
That left an opening for Davis, who posted his new number on Instagram.
"Taking the number all the way back to elementary school!" Davis wrote.
Davis was the No. 1 overall pick in 2012. He is a six-time All-Star who averaged 25.9 points, 12.0 rebounds, 3.9 assists and 2.4 blocked shots in 56 games last year.
The Lakers went 37-45 last season and have not made the playoffs since the 2012-13 campaign.