The actor was flooded with flowers, phone calls and greetings cards. An admirer even cycled from Delhi to Mumbai to wish him. Another fan has planned to write a 25-km long letter and personally hand it over.
"On his birthday, the actor will be shooting for KBC 2. Later, he will leave for New York with son Abhishek to join the crew of Kabhi Alvida Na Kehna," Amitabh's office said.
The actor canceled his 64th birthday celebrations on October 11, in a show of respect for victims of the devastating earthquake that killed many in South Asia.
Son of noted late poet Harivanshrai Bachchan and Teji Bachchan, Amitabh gave up his job as a freight broker for a shipping firm at Kolkata to move to Mumbai in 1968. After months of struggle and, ironically, a rejection by All India Radio for an announcer's job and by film producers for his tall and brooding persona, Amitabh scaled dizzy heights in Bollywood using these as his assets.
Although his debut in K A Abbas' Saat Hindustani in 1969 went unnoticed, he made a mark in Hrishikesh Mukherjee's Anand. His role as the soft, unassuming 'Babu Moshai,' determined to save his friend (played by Rajesh Khanna) from terminal illness was a craze in the 1970s. Zanjeer catapulted Amitabh into the image of an angry young man, which millions of his fans still remember.
Amitabh's anger and rebellion was visible in box-office hits like Deewar and Laawaris. Though he played the 'angry young man' to perfection, he also carried off comic roles in Chupke Chupke, Amar Akbar Anthony and Mr Natwarlal with aplomb. He also did serious roles in Abhimaan and Mili. In 1983, the actor survived a near-fatal injury during the shooting of Coolie, during which thousands of fans prayed for his life.
Four of his biggest releases this year were Bunty Aur Babli and Sarkar with his son Abhishek, Black and Waqt: Race Against Time. Being chosen as the 'Superstar of the Millennium' and being immortalised at Madame Tussaud's wax museum at London, were other feathers in the actor's cap.
He also features in Amol Palekar's Paheli, which has been selected as the Indian entry in the foreign film category at the Academy Awards this year.
Amitabh became the country's most-loved television anchor with the popular game show Kaun Banega Crorepati in 2000 and is now hosting its sequel, KBC II, which went on air on August 4.
With inputs from AP