2 (二 èr)
Two is a homophone for “Jade, Pearls, Luxuriant growth” symbolizing wealth. The phrase “good things come in pairs” is of Chinese origin. Two means a pair, meaning it is good.
3 (三 sān)
The character for the number three is similar to the one for birth (生 shēng), and is therefore associated with life.
4 (四 sì)
Four is the unluckiest of numbers, because it is associated with the word for death (sǐ). Many buildings in China don’t have any floors that contain the number 4 (4, 14, 24, 34 40–49).
5 (五 wŭ)
Five could be considered both lucky and unlucky. It is lucky because it is associated with the five elements in Chinese philosophy, but that’s a story for another day. It is unlucky because it is a homophone for “dirty, filthy, foul, insult, disobedient, disappoint, to hate, mistake”
6 (六 liù)
Six is quite lucky, as it is a homophone for “lovely, beautiful, gold, fluid”.
7 (七 qī)
Also considered the luckiest number in the west, seven can be considered lucky and unlucky. It is lucky because it can mean “peace, fine jade, neat, even, togetherness”. It is unlucky because the 7th month of the Chinese calendar is “Ghost Month”. Seven is also a homophone for “grief, mourning, coldness, ridicule, to abandon, to put to rest”
8 (八 bā)
Eight is perhaps the luckiest number in Chinese culture. It sounds similar to “prosper” (发 fā) and “wealth”. Two 8’s next to each other (88) bare a visual resemblance to the character for “double happiness” (囍). Some have gone to great lengths to use the number as much as possible for good luck.
• The United Airlines flight from San Francisco to Beijing is flight 888
• A man in Sichuan paid 元1.8 million for the phone number 888-8888
• A Hangzhou man offered to sell his license plate: A88888 for 元1.12 million
• The Petronas Towers in Kuala Lumpur have 88 floors
• TD Bank’s Chinatown branch auctioned off the safe deposit box 888
9 (九 jiŭ)
Being the highest single digit number, nine is associated with royalty (.i.e. the Emperor) and is a homophone for “long lasting”. It might be etymology of the Kowloon peninsula in Hong Kong. Kowloon is Cantonese for “Jǐulóng” meaning “Nine Dragons”.
Combinations of numbers can also form homophones with hidden meanings. Some are a real stretch though.
88 (八八 bā bā)
Beyond the fact that 8 is lucky, "bā bā" sounds like "bye-bye" and therefore is often used to say goodbye when logging out of internet chat rooms.
520 (五二 wǔ èr)
Its a real stretch but some Chinese believe the word for 520 sounds like "I love [you]" (wǒ ài).
510 (五一 wǔ yī)
Another homophone for "I love you"
There are probably hundreds of others out there. Virtually any number or number combination can have some abstract meaning.