Billionaire Richard Branson has some advice for Tesla CEO Elon Musk.

Musk, whose behavior has come under scrutiny this past year, admitted recently that he has been working long hours to keep the electric car company alive.

"The only advice I'd give him is not to burn himself out. Delegate, surround himself with really good people," Branson told CNBC on Thursday.

Branson also cautioned Musk on his social media habits. Tweeting at 3 in the morning "can be quite dangerous," said the Virgin Group founder. "But I suspect he realizes that."

Musk and Branson have a lot in common. Both men are serial entrepreneurs and are considered visionaries.

In fact, Branson called Musk an "extraordinary individual" and said he sees Musk as a "young version" of himself.

They are also competing in the space tourism business. On Thursday, Branson's Virgin Galactic completed its longest rocket-powered flight ever, bringing itself another step closer to bringing tourists to space. Branson told CNBC's "Power Lunch" afterwards that he hopes to go into space next year.

Musk is the founder and CEO of Space X, which has also launched several rockets this year in its quest to ultimately bring people to space.

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Musk, however, has hit a few rough patches in 2018. A tweet from August, saying he was taking Tesla private, led to a multi-million dollar settlement with the Securities and Exchange Commission and Musk stepping down as chairman.

He also gave an interview to the New York Times in August describing the year as "excruciating" and appeared to smoke pot and drink whiskey during comedian Joe Rogan's podcast in September.

Earlier this week, Musk told CBS's "60 Minutes" he was pushing himself hard as Tesla struggled to ramp up production of its Model 3 car.

"I think there was like literally one week where I actually worked 120 hours and just didn't leave the factory. I didn't even go outside," Musk told Leslie Stahl.

Musk has since cut back his hours, acknowledging his schedule was not sustainable. In his interview with Stahl, he also stressed he does not smoke marijuana. "As anyone who watched that podcast can tell, I have no idea how to smoke pot or anything."

Branson is confident Musk will make it all work.

"He's young. He'll continue to do extraordinary things for many, many years to come."