In a move that has been hotly anticipated, Facebook has filed with the SEC to raise $5 billion in an initial public offering of stock in the United States. The company will trade with the stock symbol of “FB”.

Yesterday, it had been predicted that Facebook would file initial paperwork for its public offering, seeking to raise $5B in its IPO bid. Morgan Stanley grabbed the lead bookrunner role and Goldman Sachs, Bank of America, Merrill Lynch, Barclays Capital and JP Morgan finished off the total of six initial bookrunners.

The timeline puts Facebook’s public offering on the slate for mid-May. It now has to enter a mandated quiet period, so it could mean that Timeline is the last new product we see from the company until that period is up.

To run through the numbers, Facebook is saying in the filing that it has 845 million active monthly users. The company made $3.71 billion in revenue, with $1 billion in profit in 2011, nearly doubling from 2010. At present, the company has $3.9 billion in cash on hand.

Founder and CEO, Mark Zuckerberg, owns 28.4% of the company, drawing a $483,000 salary, with a $220,000 bonus in 2011. The company even credits Zynga with providing 12% of its revenue in 2011 (more on that here).

The company will focus on mobile, in the future, and with good reason:

“We had more than 425 million MAUs who used Facebook mobile products in December 2011. We anticipate that the rate of growth in mobile users will continue to exceed the growth rate of our overall MAUs for the foreseeable future, in part due to our focus on developing mobile products to encourage mobile usage of Facebook.”

The filing then goes on to explain, as a risk factor, that Facebook relies heavily on the interoperability of mobile OSs with its application:

“We are dependent on the interoperability of Facebook with popular mobile operating systems that we do not control, such as Android and iOS, and any changes in such systems that degrade our products’ functionality or give preferential treatment to competitive products could adversely affect Facebook usage on mobile devices.”

We’ll continue digging, but for now make sure to read the interesting facts that we’re finding in Facebook’s S-1.