Chinese numerology

Some numbers are believed by some to be auspicious or lucky (吉利, pinyin: jílì; Cantonese Yale: gātleih) or inauspicious or unlucky (不吉, pinyin: bùjí; Cantonese Yale: bātgāt) based on the Chinese word that the number sounds similar to. The numbers 6 and 8 are widely considered to be lucky, while 4 is considered unlucky. These traditions are not unique to Chinese culture, with other countries with a history of Han characters also having similar beliefs stemming from these concepts.

The number 0 (零, pinyin: líng) is the beginning of all things and is generally considered a good number, because it sounds like 良 (pinyin: liáng), which means 'good'.

The number 1 (一, pinyin: yī; Cantonese Yale: yāt) is neither auspicious nor inauspicious. It is a number given to winners to indicate first place. But it can also symbolize loneliness or being single. For example: November 11 is the Singles' Day in China, as the date has four '1's.

The number 2 (二, cardinal, pinyin: èr or 兩, used with units, pinyin: liǎng) is most often considered a good number in Chinese culture. In Cantonese, 2 (二 or 兩, Cantonese Yale: yih or léuhng) is homophonous with the characters for "easy" (易, Cantonese Yale: yih) and "bright" (亮, Cantonese Yale: leuhng), respectively. There is a Chinese saying: "good things come in pairs". It is common to repeat characters in product brand names, such as the character 喜 (pinyin: xǐ; Cantonese Yale: héi; lit. 'joy'), can be repeated to form the character 囍 (pinyin: shuāng xǐ; Cantonese Yale: sēung héi; lit. 'double happiness').

The number 3 (三, pinyin: sān; Cantonese Yale: sāam) sounds like 生 (pinyin: shēng; Cantonese Yale: sāang), which means "to live" or "life" so it's considered a good number. It's significant since it is one of three important stages in a person's life (birth, marriage, and death).
On the other hand, number 3 (三,pinyin: sān; Cantonese Yale: sāam) sounds like 散 (pinyin: sàn; Cantonese Yale: saan) which means "to split" or "to separate" or "to part ways" or "to break up with" so it is a bad number too.

While not traditionally considered an unlucky number, 4 has in recent times, gained an association with bad luck because of its pronunciation, predominantly for the Cantonese.

The belief that the number 4 is unlucky originated in China, where the Chinese have avoided the number since ancient times. The Chinese interpretation of 4 as unlucky is a more recent development, considering there are many examples, sayings and elements of the number 4 considered as auspicious instead in Chinese history.

The number 4 (四, pinyin: sì; Cantonese Yale: sei) is sometimes considered an unlucky number particularly in Cantonese because the way it is pronounced in the Cantonese dialect is nearly homophonous to the word "death" (死 pinyin: sǐ; Cantonese Yale: séi).