Elon Musk is kind of homeless in Silicon Valley, says Larry Page

Elon Musk may have a net worth upward of $13 billion, but he is not above hitting up his friends to crash in their spare bed-rooms.

Musk owns a $17-million home in Los Angeles with gorgeous ocean views, but he doesn't have any property in Silicon Valley, where his company Tesla Motors is based.

"He's kind of homeless, which I think is sort of funny," Google CEO Larry Page told Ashlee Vance for Vance's soon-to-be-released book, Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future.

When Musk visits every week, he sometimes pings Page, who owns a six-bedroom home in Palo Alto as well as a second eco-friendly mansion on the same property.

"He'll email and say, 'I don't know where to stay tonight. Can I come over?'" Page says. "I haven't given him a key or anything yet."