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' which stand for singles.
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 joy').
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).
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 one floors. Similarly in Vietnamese, the number 4 (四) is called tứ in Sino-Vietnamese, which sounds like tử (死) (death) in Vietnamese.
The number 4 can also symbolise luck, prosperity and happiness in Chinese culture. In the musical scale, 4 is pronounced Fa, which sounds like 发 (fortune) in Mandarin. In this case, some Chinese people regard 4 as the propitious and lucky number. There is also an old Chinese idiom 四季发财 (To be Wealthy All Year).
In traditional Chinese history and other Chinese dialect groups like the Teochew people, the number 4 is considered a very lucky and auspicious number. For starters, it is an even number. There is a preference of even numbers over odd numbers. Many historical and philosophical Chinese concepts are also in groups of 4.
Another common explanation is that the number 4 in Teochew sounds like or rhymes with the word "happiness" or "joy" (喜 Teochew: hi2).
Finally, another plausible explanation is that in the Teochew dialect, the number 4 (Teochew: si) is similarly pronounced to the word "silk" (絲 Teochew: si1) or "Emperor's seal" (璽 Teochew: si2), a symbol of royalty, power and prosperity.
In Teochew culture, it is acceptable and considered lucky to give "red packets" of money (紅包 Teochew: ang5 bao1) in monetary groups of 4 (e.g. $4, $40, $44, $440 etc...) during Chinese New Year and other festivities like weddings. Stacks of 4 mandarin oranges (Citrus reticulata) are often presented on grand or formal Teochew occasions, the most common stack configuration with 3 mandarin oranges below and 1 on top.
The house numbers with 4 and 44, while shunned by the Cantonese, are often chosen by Teochews for its particular auspicious connotations. Heng Pang Kiat JP Esq. (aka Hing Pang Kiat) (c 1856 - 1930), a prominent Teochew businessman and property developer in Singapore, had specially picked the house number 44 on Emerald Hill, even though he had a choice of house numbers from 38 to 52, from his property developments in Emerald Hill.
There is an exception for the Cantonese with the house number 54, which is considered very lucky as it sounds like 唔死 (m̀ séi) meaning "Will not die and shall live forever". The number 9 is considered the highest number representing great success in Chinese numerology, thus the number 54 can also be interpreted as 5 + 4 = 9, to mean great success.
The transmission of this superstition could also be linked to religion. Buddhism played a significant role in the spread of Chinese characters and culture across the region. In Japan, the idea that the number 4 was once considered auspicious is documented in the Kojiki, emphasizing its connection to good fortune. However, as Chinese influence grew, and the pronunciation became closer to "shi," it began to be associated with death. In Korea, Buddhism's influence was more prominent when the religion was first introduced, and in Vietnam, the Sino-Vietnamese pronunciations might have contributed to this superstition. Buddhism provided the platform for discussing death, giving rise to this cultural foundation.
The number 5 (五, pinyin: wǔ; Cantonese Yale: ńg) sounds like "me" in Mandarin (吾, pinyin: wú; lit. 'me') and Cantonese (唔, Cantonese Yale: m̀; lit. 'not'). It is considered a lucky number. Thus, the number is used for the measurements and naming of the presidential car of Xi Jinping, or the Hongqi L5.
Five is also associated with the five elements (Water, Fire, Earth, Wood, and Metal) in Chinese philosophy, and in turn was historically associated with the Emperor of China. For example, the Tiananmen gate, being the main thoroughfare to the Forbidden City, has five arches.
The number 6 (六, pinyin: liù) in Mandarin sounds like "slick" or "smooth" (溜, pinyin: liū). In Cantonese, 6 (Cantonese Yale: luk6) sounds like "good fortune" or "happiness" (祿, 樂 Cantonese Yale: lok6). Therefore 6 is considered a good number for business.
The number 7 (七, pinyin: qī) in Mandarin sounds like "even" in Mandarin (齊, pinyin: qí), so it is a good number for relationships. It also sounds like "arise" (起, pinyin: qǐ) and "life essence" (氣, pinyin: qì) in Mandarin. Seven can also be considered an unlucky number since the 7th month is a "ghost month". It also sounds like "to deceive" (欺, pinyin: qī) in Mandarin. In Cantonese, 7 (Cantonese Yale: chāt) sounds like 𨳍 (Cantonese Yale: chat), which is a vulgar way of saying "penis".
The number 8 (八, pinyin: bā; Cantonese Yale: baat) sounds like "發" (pinyin: fā; Cantonese Yale: faat; lit. 'to prosper'). There is also a visual resemblance between 88 and 囍 (pinyin: shuāng xǐ; Cantonese Yale: sēung héi; lit. 'double joy'), a popular decorative design composed of two stylized characters 喜 (pinyin: xǐ; Cantonese Yale: héi; lit. 'joy').
The number 8 is viewed as such an auspicious number that even being assigned a number with several eights is considered very lucky.
The number 9 (九, pinyin: jiǔ; Cantonese Yale: gáu) was historically associated with the Emperor of China, and the number was frequently used in matters relating to the Emperor, before the establishment of the imperial examinations officials were organized in the nine-rank system, the nine bestowments were rewards the Emperor made for officials of extraordinary capacity and loyalty, while the nine familial exterminations was one of the harshest punishments the Emperor sentenced; the Emperor's robes often had nine dragons, and Chinese mythology held that the dragon has nine children. Also, the number 9 sounds like "long lasting" (久, pinyin: jiǔ; Cantonese Yale: gáu), so it is often used in weddings.
In Cantonese, the number 9 is also a vulgar way of saying penis (𨳊, Cantonese Yale: gāu), similar to 7 as well, with 9 referring to an erect penis instead.