In China, what number is considered unlucky because its pronunciation is similar to that for the word "death"?

In Chinese tradition, certain numbers are believed by some to be auspicious or inauspicious, based on the Chinese word that the number sounds similar to. The numbers 6, 8 and 9 are generally considered to be auspicious, while 4 and 7 are considered inauspicious.

The number 4 is considered an unlucky number in Chinese because it is nearly homophonous to the word "death" . Thus, some buildings in East Asia omit floors and room numbers containing 4, similar to the Western practice of some buildings not having a 13th floor because 13 is considered unlucky. Where East Asian and Western cultures blend, such as in Hong Kong, it is possible in some buildings that the thirteenth floor along with all the floors with 4s to be omitted. Thus a building whose top floor is numbered 100 would in fact have just eighty floors.