It's almost inevitable: release a new iPhone, break a sales record. This year, Apple released a pair of iPhones, the 5S and 5C, and unsurprisingly sales have been strong. Apple sold a combined 9 million iPhone 5S and 5C smartphones over the handsets' first full weekend of sales — the most it's ever done. That's enough for Apple to have already sold out of its initial stock of the iPhone 5S, though the company does say that retail stores are regularly receiving more shipments of the phone. "The demand for the new iPhones has been incredible," Apple CEO Tim Cook says in a statement. "We appreciate everyone’s patience and are working hard to build enough new iPhones for everyone.”

Higher than ever, but difficult to really put in perspective

The 9 million figure compares quite favorably to the five million iPhone 5 that Apple sold in the opening sales weekend last year, and four million iPhone 4S it sold during the equivalent period in 2011. However, it's difficult to make year-over-year comparisons, as Apple's launch markets have changed each year. This year, the company made both its new iPhones available in China on day one for the first time. Apple's press release also doesn't reveal what the split of phones was, so we don't know how well the 5C or 5S did individually either. Having said that, analytics firm Localytics estimates that the 5S outsold the 5C by nearly three-and-a-half to one, suggesting that the iPhone 5S accounted for about 6.95 million of the total iPhone sales. Apple has adjusted guidance for its Q4 earnings based on the new information, and is now suggesting that it's likely to end up "near the high end" of a previously announced range of $34 billion to $37 billion in revenue. The company's stock has jumped up over 6 percent pre-market in light of the news, and is approaching a $500 share price.

Apple also revealed that iTunes Radio has been something of a success right out the gate. It's already seen over 11 million unique listeners, with the launch weekend's most listened song being a fairly new Drake track, "Hold On, We’re Going Home." Its new operating system, iOS 7, has also been off to a strong start as well, with over 200 million devices already running it under a week after launch. According to Apple, that quick proliferation makes it the fastest software update adoption in history. Not surprisingly, Apple is pleased with the response it's seen. "This is our best iPhone launch yet," says Cook.

Update: Apple's stock opened at a share price of $496 today, after closing at $467.41 on Friday. The company's stock peaked just above $500 the day before it announced the new iPhones, but had slumped in the days that followed. Though Apple saw some increase late last week, today's opening marks a big jump as investors react to news of the latest iPhones' sales figures.

Additional reporting by Jacob Kastrenakes.