The figures represent roughly a quarter of Apple's total global App Store earnings.
Cook shared the data on Sunday during a speech at China's top public cyber policy forum, organized by the Cybersecurity Administration of China (CAC), which oversees internet regulation including censorship.
The report released on Monday by the Chinese Academy of Cyberspace Studies, said China's digital economy reached 22.58 trillion yuan ($3.4 trillion) in 2016.
Xi said that online developments were raising many new challenges to sovereignty and security, and China was "willing to work with the worldwide community to respect cyberspace sovereignty and promote partnerships".
The two companies had a dispute earlier, but made peace after Apple started accepting WeChat payments from August this year as several apps on the Apple's app store were made by Tencent, which generated considerable revenue for both the firms.
Cook said he could not be happier with how the iPhone X was doing in China, Apple's third-largest region by sales although it has lost market share in recent years as handsets from local rivals gain traction.
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China confirms that its digital economy accounts for almost a third of gross domestic product, according to a report unveiled in the eastern city of Wuzhen during the fourth World Internet Conference where it declared that Chinese cyberspace is "open" - but subject to controls for the greater good. "We are proud to have worked alongside many of our partners in China to help build a community that will join a common future in cyberspace".
The tacit endorsement of the event by top US tech executives comes as China introduces strict new rules on censorship and data storage, causing headaches for foreign tech firms permitted to do business in China and signalling that restrictions banning others are unlikely to be lifted any time soon.
Pichai did not give a speech but appeared on a group panel alongside Xiaomi founder Lei Jun. Google is believed to be seeking to return to China after withdrawing from it years ago because of disagreement over censorship and its cyber attacks.
"A lot of work Google does is to help Chinese companies", Pichai said.
"Many small and medium-sized businesses in China take advantage of Google to get their products to many other countries outside of China", Pichai told the meeting, Hong Kong-based South China Morning Post reported.
He said: "Global cyberspace governance has no onlookers - we are all participants, ' adding that 'all parties" should have a say over how the internet is managed across the world.