536 100。 According to the postal code database information, Hepu, Beihai, Guangxi is located in Hepu County, Beihai City, Guangxi Zhuang Autonomous Region, with the postal code of 536 100. Postal code is a coding method that a country or region divides the whole country in order to realize the automation of mail sorting and the digitalization of postal network and speed up the delivery of mail.