Modi, who joined Viber Public Chat on January 26, 2015, has seen his following swell to more than 8.5 lakh followers on Viber, it said in a release.
Launched last year, the chat allows users to discover, share and follow live discussions from a wide variety of known personalities, celebrities and brands across genres like music, sports, politics, fashion and entertainment, it added.
Viber is a mobile app with 37 million Indian users offering free messaging and HD-quality calls and more than 50 public chat platforms.
Modi has a huge following on social media platforms like Facebook and Twitter and is among the top three politicans globally, in terms of fan following on social media.