How many iPhones did Apple sell?

LOS ANGELES — Can you name three new features on the iPhone 6S and iPhone 6S Plus that you’ve used?

Probably not. But it doesn’t matter. Analysts expect the new version to outsell last year’s iPhone 6, which was Apple’s best-selling iPhone ever.

Apple announces fourth-quarter results Tuesday, and with the stats, the company will say how many iPhones sold in the quarter. Wall Street expects sales of 48 million to 49 million, which would greatly top last year’s shipment of 39 million iPhone 6 models in its first quarter. It's expected to make $1.88 a share on sales of $51.1 billion, according to analysts polled by Thomson Reuters.

Still, the growth for the new phone is “modest” at 3% compared to 35% for the iPhone 6, says Gene Munster, an analyst with Piper Jaffray.

Though the S model traditionally doesn’t wow consumers and critics as much as the off-year new number models — which generally offer a redesign — this year’s S has a few things going for it.

Munster says availability in China (the 6 wasn’t until December, three months after its launch) and better availability contributed to stronger sales for iPhone 6S.

Additionally, many folks were coming out of a two-year contract and used the opportunity to upgrade to bigger phones, the iPhone 6 and 6 Plus as well as the new iPhone 6S models.

Apple has “a massive green field opportunity ahead of itself on the high-end smartphone market,” Daniel Ives, managing director of FBR Capital Markets, said in a note to investors.

For the Christmas quarter last year, Apple sold a record 74.5 million iPhone 6 models. Ives and Munster are looking to see if Apple offers guidance in the call that would top 75 million for iPhone 6S.

“What will really tell the story of the iPhone 6S is what the guidance will be,” Munster says.

Wall Street expects Apple to report revenue of $74 billion to $77 billion in the final three months of the year, compared to $74 billion in the year-ago quarter, with earnings of $3.21 a share, up from $3.06 a year ago.

On Tuesday, Apple will also report sales of Macintosh computers and iPads, but has declined to share sales for the new Apple Watch, which launched in the spring to so-so reviews and scarce product availability.

Munster pegs Apple Watch sales to date at 5.5 million.

Apple’s latest new product, a revamped Apple TV set-top box with voice-activated Siri remote, goes on sale this week.

Meanwhile, with 700 million iPhones sold to date, when will Apple announce the next big milestone: Sales of 1 billion iPhones?

Here’s a clue: Apple has sold 221 million iPhones in the last 12 months.

If Apple indeed reports sales of 50 million iPhones on Tuesday, that gets the company to 750 million, and if history repeats itself, Apple could get to 1 billion by next fall.

“It’s probably five quarters away,” Munster predicts.

Readers: Think it will come sooner? Later? Not at all? Let’s hear from you? Look for me on Twitter, where I’m @jeffersongraham.