Why does 666 represent bad luck?

Because 666 is the code name of Satan, and 666 is the number of the devil in Christianity.

This concept is influenced by national culture, but in China 666 means good luck. So this varies from person to person, so don't take it too seriously.

According to the Bible, three consecutive sixes are the code name of the devil, so most westerners, including celebrities and politicians, have always been very taboo about "666". It is said that there was once a section of highway in New Mexico called 666, which was also called "Devil's Highway" because of its code name 666. As a result, this road scared away many tourists because of its name, and finally the government was forced to rename this road 49 1.