Facebook founder Mark Zuckerberg has refinanced a $5.95 million mortgage on his Palo Alto, Calif., home with a 30-year adjustable-rate loan starting at 1.05 percent, according to public records.

Zuckerberg, 28, is the world's 40th wealthiest person, with an estimated net worth of $15.7 billion.

The five-bedroom, 5 ½-bath house was built in 1903 on a 9,011-square-foot lot. The two-floor white wood-sided home is ensconced behind a gated drive and a wall of groomed shrubbery.

Monthly principal and interest mortgage payments would start at $19,275.