Megastar Amitabh Bachchan has become the first Bollywood personality to score 20 million followers on Twitter and has thanked his fans and well-wishers on reaching the milestone.The 73-year-old thespian, who has given hits like "Sholay", "Deewar" and "Piku", is ahead of Indian Prime Minister Narendra Modi, who has 18.8 million followers, as well as actors Shah Rukh Khan with 18.6 million, Aamir Khan 16.9 million, Salman Khan 16.8 million and Priyanka Chopra with 13.2 million followers respectively. Big B took to Twitter on Tuesday night to express his excitement of getting 20 million followers on the micro-blogging website."Badumba! 20 million! Thank you all... Now to 30 million! And your time starts now!" Amitabh tweeted. Amitabh's Twitter account went live in May 2010, and the actor has ever since been staying in connection with his fans, whom he fondly calls his "ef" or his "extended family".On the work front, Amitabh will next be seen in "TE3N" directed by debutant Ribhu Dasgupta. The film also features actors Vidya Balan and Nawazuddin Siddiqui.He is currently busy shooting for Shoojit Sircar's next production venture "Pink."