SAN FRANCISCO — Max Levchin is not easily distracted from his work.

A few years ago, Mr. Levchin, one of the young princes of Silicon Valley, bought his first home, a 12-room Edwardian high atop a hill here, for $3.4 million. But Mr. Levchin, who made a fortune at age 27 selling PayPal, the online payment service he helped start in 1998, never moved in. He sold it two years later without having slept there for even one night.

Since then, Mr. Levchin has moved into his second home, a more expensive one found for him by Nellie Minkova, his girlfriend of eight years who has become his fiancée. But so consumed is he by work on his second company, an Internet start-up focused on sharing photos and videos, that the cartons that contain what Mr. Levchin described as “85 percent of my worldly possessions” are still stacked in his living room, five months after moving day.

Mr. Levchin, who is now 32, is typical of a new generation of junior titans in Silicon Valley who might be called the prematurely rich — techies worth tens of millions of dollars, sometimes more, at an age when many others are just starting to figure out what to do with their lives.

The Internet, a low-overhead medium with a global reach, has greatly accelerated the wealth creation phenomenon, producing a larger breed of multimillionaires even younger and richer than in the past.