As megastar Amitabh Bachchan turned 73 on Sunday, tinsel town celebrities like Rishi Kapoor, Madhuri Dixit, Karan Johar and Anupam Kher took to Twitter to wish "the indisputable superstar of the country".

Honoured with Padma Vibhushan, the country's highest civilian honour, and Knight of the Legion of Honour by France for his exceptional career in the world of cinema, Big B has starred in films like “Deewar”, “Zanjeer”, “Sholay”, “Don”, “Black”, “Sarkar”, “Agneepath”, “Paa” and “Shamitabh” in his illustrious career.

He was last seen on the silver screen in Shoojit Sircar's “Piku”, and will next be seen in Bejoy Nambiar's “Wazir”, which is slated to release on December 4.

Here is what the B-Town tweeted:

Rishi kapoor: Birthday wishes to Amitji on this day. I erred by wishing him day before. A true role model for all! 

Madhuri Dixit-Nene: Here's wishing @SrBachchan a very Happy Birthday. Thank you for always being an inspiration. #HBDAmitabhBachchan 

Karan Johar: Happy birthday to the father of the fraternity...the indisputable superstar of the country...a legend...@SrBachchan 

Farah Khan: Happy Birthday to the true Rock Star!@SrBachchan .. Keep rocking Amitji 

Anupam Kher: Happy birthday @SrBachchan Ji. May you have a long, happy and peaceful life. Love and regards always.

Shahid Kapoor: Happy birthday to the legend @SrBachchan. Thank you sir for being such an inspiration.

Prakash Jha: @SrBachchan Sir many happy returns of the day! Wish you a long, happy and fulfilling life! God bless!

Kapil Sharma: Happy birthday legend @SrBachchan keep trying...One day you will learn how to pout... Hahahahaha...Love and regards 

Shilpa Shetty Kundra: On the sets with @srbachchan, he has an aura about him that makes every heart skip a beat, mine too.

Bipasha Basu: Happy Birthday to the coolest, the most charming, actor extraordinaire - the legend, @SrBachchan Love you Sir!

Sidharth Malhotra: My inspiration, an institution, a legend! Happy 73rd Birthday @SrBachchan sir love and respect.

Parineeti Chopra: Happy birthday to the most humble legend @SrBachchan! So much to learn from you sir. All the health, happiness and success to you! 

Alia Bhatt: Happy birthday to our biggest inspiration, the coolest and probably the definition of "Epic" @SrBachchan! 

Divya Dutta: @SrBachchan to sir with love... Many many happy returns of the day.

Ehsaan Noorani: A Very Happy Birthday to you sir @SrBachchan.

Sajid Khan: Happy birthday to a living legend @SrBachchan...have a great one sir!

Rohit Roy: Happy birthday Amit ji...Have a happy and healthy year ahead.. Love and warmth.. @SrBachchan

Ken Ghosh: Wishing the one! The only! @SrBachchan a very very happy birthday!

Sujoy Ghosh: happy birthday @SrBachchan... you remain the undisputed Guru.

Manish Paul: Happy birthday @SrBachchan sir...I am also cutting a cake to celebrate your birthday! Love you sir 

Shirish Kunder: Wish you a very Happy Birthday, @SrBachchan sir! Regards