HANGZHOU, China — Unmarried men across China used to spend Nov. 11 lamenting their single status with a drink. Now that unofficial holiday has become the world’s largest online shopping event.

On Monday, China’s biggest online shopping company processed more than $5.75 billion in its online payments system — a record for a single day anywhere in the world, surpassing by two and a half times the total for American retailers last year on so-called Cyber Monday.

The company, Alibaba, which owns Tmall and other e-commerce sites, first latched onto so-called Singles’ Day, symbolized by the four lonely 1s of 11/11, five years ago. The company realized men could just as easily seek solace by buying electronic devices and other gear on its sites. Soon enough, just about everyone else did, too.

Alibaba reported Monday that it had 402 million unique visitors to its sites — more than a third of the adult population in China — and prepared 152 million parcels for shipping. Tmall.com, one of Alibaba’s shopping sites, said Chinese bought 1.6 million bras, which it helpfully noted would reach three times the height of Mount Everest if folded and stacked, and two million pairs of underpants, which if linked together would stretch 1,800 miles, all before the lunch hour.