Apple posted the biggest profit in corporate history last quarter after selling a record number of iPhones.

Apple (AAPL) sold 74.5 million iPhones in the last three months. That helped Apple's profit soar more than 37% to $18 billion. That's larger than Gazprom's $16.2 billion profit during the first quarter of 2011 -- the previous profit record posted by a corporation.

Apple also posted a stunning $74.6 billion in sales, up nearly 30% from the same period last year. That's not close to a global corporate record, but it's the best quarterly revenue Apple ever posted.

"Interest in Apple products is at an all time high ... shattering our high expectations," said CEO Tim Cook on a conference call with analysts. "This volume is hard to comprehend."

Shares of Apple soared 9% in premarket trading.

Mac sales grew about 15% to a record 5.5 million. Apple said iTunes sales also hit a record high, while iPad sales continued to slump, falling 18% to 21.4 million

But the story was the iPhone.

Cook noted that Apple sold an average of 34,000 iPhones every hour.

The iPhone is already the single best-selling gadget of all time. But this past quarter, the iPhone outsold some gadgets made by entire industries.

The whole TV industry sold fewer than 60 million televisions last quarter, according to IHS. The tablet industry sold just 54 million tablets, IDC reported.

In fact, the iPhone very nearly outsold the entire PC industry. Computer makers sold fewer than 84 million desktop and laptops last quarter, according to Gartner. That's every HP (HPQ), Lenovo, Mac, Dell -- everything.

Related: Can Apple live up to the iHype?

Apple had never sold more than 51 million iPhones in a quarter, which it accomplished a year ago. But that was before the deal with China's biggest mobile provider, China Mobile (CHL), which went into effect in the first quarter of 2014.

That deal benefited Apple in a big way last quarter. Apple's China sales soared 70% last quarter.

Making such gigantic inroads in China was once believed impossible. Apple's brand did not hold the same cache as some Chinese smartphone makers, including Xiaomi, Lenovo and Huawei. And those brands heavily discount their phones, making them far more accessible to the masses than Apple makes the iPhone.

Apple also rolled out the new iPhone 6 to other countries last quarter faster than it had in previous years, helping Apple boost its iPhone sales. The iPhone 6 is available in 130 countries. Apple also said its supplier efficiencies helped the company manufacture 7 million more iPhones than it had expected to make last quarter.

Related: Microsoft sales soar ... no thanks to Windows

But the iPhone's expected success isn't solely due to China, the global market or supply chains.

The iPhone 6 has proven extremely popular with customers who were holding out for a bigger Apple smartphone. The 4.7-inch screen competes much better with some larger Android smartphones, and the superior camera has helped some would-be defectors stick with the iPhone brand.

The new iPhone didn't just grow Apple's smartphone volume -- it also grew revenue by convincing customers to spend more money on their devices. The even giant-er, $100-more-expensive iPhone 6 Plus has also helped drive sales, accounting for about a quarter of all iPhones sold last quarter, Nomura Securites analyst Stuart Jeffrey believes (Apple doesn't break out iPhone 6 Plus sales separately).

Even better for Apple, Jeffrey expects that about half of all customers spent an extra $100 on their iPhone 6 and 6 Plus devices to upgrade to 64 gigabytes of storage -- four times the amount of the standard 16 GB model. Last fall, Apple doubled the storage size of its mid-tier iPhone. Previous editions had just 32 GB of storage, so customers jumped at a good value.

All the good iPhone news is why Apple posted a record quarter: About two-thirds of Apple's sales and earnings come from the iPhone.

But Apple has more potential billion-dollar products on the way. Tim Cook announced Tuesday that the Apple Watch will go on sale in April.