Stanford University (officially Leland Stanford Junior University, colloquially the Farm) is a private research university in Stanford, California, in Silicon Valley, 20 miles (30 km) outside of San Jose. Because of its academic strength, wealth, and proximity to Silicon Valley, Stanford is often cited as one of the world's most prestigious universities. Stanford faculty and alumni have founded a large number of companies, these companies produce more than $2.7 trillion in annual revenue. It is the alma mater of 30 living billionaires, 17 astronauts, and 20 Turing Award laureates.