Apple has just announced it has sold over four million of its new iPhone 4S, just three days after its launch on Friday, October 14. Plus, the Cupertino, California-based company has announced that 25 million current iDevice owners have already upgraded to iOS 5, five days after the latest operating system was made available to the public.

According to Philip Schiller, Apple’s senior vice president of Worldwide Product Marketing:

“iPhone 4S is off to a great start with more than four million sold in its first weekend—the most ever for a phone and more than double the iPhone 4 launch during its first three days. iPhone 4S is a hit with customers around the world, and together with iOS 5 and iCloud, is the best iPhone ever.”

As a reminder, the iPhone 4S is available now in the U.S., Australia, Canada, France, Germany, Japan and the UK. It goes on sale October 28 in 22 more countries, with 70 more going online before the end of 2011.