Bollywood megastar Amitabh Bachchan, who joined Twitter a few days ago, congratulated actor Shah Rukh Khan for having as many as 400,000 followers on the microblogging site.

"Congrats!! you crossed 400, 000... meri gaadi thoda dheeli chal rahi hai (I'm at a slower pace at the moment), " the 67-year-old posted on his Twitter page.

Amitabh, who has become a regular on the site now, presently has 98, 228 followers. While he writes on his Twitter page couple of times during the day, he also has a blog, a voice blog and a mobile blog.

Amitabh's son Abhishek too has an account on Twitter.