Apple says it has sold 1 million iPads just 28 days after the Wi-Fi version of the product was released last month. The tablet is selling at twice the rate of the first iPhone model, which took 74 days to reach a million sales when it came out in 2007.

Apple CEO Steve Jobs said in a statement that “demand continues to exceed supply” for the company’s iPad device.

According to Apple, iPad users have already downloaded more than 12 million apps from the App Store and over 1.5 million ebooks from its iBookstore. 

Developers have created more than 5,000 apps tailored to the iPad, which also can run most of the 200,000 apps created for the iPhone and iPod touch.

The 3G-enabled version of Apple’s iPad came out on Friday. In a note to investors, Piper Jaffray analyst Gene Munster estimated that about 300,000 iPad 3G devices were sold in its opening weekend.