Kulappulli Leela (who plays Kaalaiyan's grandmother) did a blink-and-you-miss role in Rajinikanth's 1995 blockbuster Muthu. She reminded him about this role during Annaatthe shooting.
The first Rajinikanth film since 'Sivaji: The Boss' (or 'Kuselan', even though it features the superstar in an extended cameo) to not have a simultaneous Hindi-dubbed release, and the first since 'Baba' (2002) to not have a Hindi dubbed version at all. The Hindi version of 'Sivaji' released in 2010, two and a half years after its original release.
Rajinikanth worked for more than 14 hours per day in order to complete his shooting schedule as already film release got delayed due to COVID-19 pandemic. Due to his restless shooting schedule, Rajinikanth got hospitalized on 25 December 2020. Following his health recovery, he resumed the shooting on March 15 2021.