Donald Trump, who has been a real estate developer, entrepreneur and host of the NBC reality show, "The Apprentice," is now running for president of the United States. The 69-year-old billionaire has already brewed controversy over a year before the election, making himself stand out amongst his other Republican candidates. Here are some things you need to know about him before the primaries and election in 2016:

1. Trump was an active member of the “birther” movement that questioned President Obama’s birthplace.

He even sent investigators to Hawaii to back up his accusations. When Obama publicly released his birth certificate in 2014, Trump referred to at his “so-called birth certificate, or whatever it was.”

2. Although he touts his enormous wealth as a reason he should be elected president, Trump's companies have filed for bankruptcy on four separate occasions.

In 1991, Trump’s Taj Mahal in Atlantic City filed for Chapter 11 bankruptcy. In 1992, Trump Plaza in Atlantic City’s turn took a turn for the worst, and Trump gave up his 49 percent state in the hotel to lenders. Trump Hotels and Casinos Resorts filed for bankruptcy in 2004 and most recently, Trump Entertainment Resorts filed in 2009.

3. The Trump brand spans a wide variety of industries including real estate, hospitality, entertainment, mortgages, restaurants and catering, ice cream, online travel, menswear, fragrance, golf, home furnishings, transportation, model management, vodka, and more.

4. In the 2012 GOP primary rise of candidates, it became apparent that earned media and even outside Super PAC money can only take a candidate so far.

Organized ground game and voter targeting efforts backed by in-state staff are critical in the long-term, and to date, the Trump campaign does not appear to have invested in a serious campaign infrastructure.

5. Prior to his run for the presidential ticket for the Republican party, Trump financially supported both the Democrat and Republican parties over a period of two decades.

6. From 1990 through 2009, Trump personally donated a total of just $3.7 million to his foundation, which he created in 1987.

In fact, the billionaire is not even the largest contributor to his own charitable organization, The Donald J. Trump Foundation.

7. He attempted to sue writer Timothy L. O'Brien for $5 billion in 2005 when the author wrote that Trump was a millionaire rather than a billionaire in his book, TrumpNation: The Art of Being The Donald.

Later, Trump states his reasonings for the lawsuit were that "his reputation and brand were damaged." Later, he acknowledged that his net worth fluctuates depending on the markets.

8. In 1989, Trump paid $85k for an ad campaign promoting the death penalty for the five boys aged 14-16 who were accused of raping a woman in Central Park.

The group known as the "Central Park Five" were later found not guilty and were exonerated of all charges. Donald Trump refused to apologize for the ad campaign, and he has not apologized even to this day.

9. During an interview with Don Lemon, Trump reflected on his conversation with Fox News host Megyn Kelly.

In the interview, Trump tells Lemon, “She gets out and she starts asking me all sorts of ridiculous questions. You could see there was blood coming out of her eyes, blood coming out of her wherever.”

10. During his June 16 presidential announcement speech, Trump stated: “When Mexico sends its people, they're not sending the best."

They're not sending you, they're sending people that have lots of problems and they're bringing those problems. They're bringing drugs, they're bringing crime. They're rapists and some, I assume, are good people, but I speak to border guards and they're telling us what we're getting."

There you have it, folks.