Lucky and unlucky numbers around the world

Published Juli 1, 2026 · By NumberWiki

Mathematically, every whole number is just a position on the number line — no luckier or unluckier than its neighbours. Culturally, that could not be further from the truth. Buildings skip floors, phone numbers sell for fortunes, and couples pick wedding dates around beliefs that are thousands of years old. Almost every one of these beliefs comes down to two things: what a number sounds like, and what it has stood for in religion and story.

Seven: the world's favourite number

7 is the closest thing there is to a universally lucky number. Ask people in almost any country to name a "lucky number" and seven is the runaway favourite. Its status is ancient and over-determined: there are seven classical planets visible to the naked eye, seven days in the week, seven notes in a musical scale, seven colours traditionally counted in a rainbow, and seven is woven all through the Bible — the seven days of creation, seven deadly sins, seven seals. Some psychologists argue seven also feels special because it is the only number from one to ten that can't be multiplied or divided to land on another number in that range, giving it a faint air of being "prime" and independent. (It is, in fact, prime.)

Four: the number of death in East Asia

In China, Japan, Korea, and Vietnam, 4 is the number to avoid — an aversion strong enough to have its own name, tetraphobia. The reason is a homophone: in Mandarin, 四 (sì, "four") sounds almost identical to 死 (sǐ, "death"); the same near-match exists in Japanese (shi) and Korean (sa). The consequences are everywhere — hospitals and hotels skip the 4th floor, apartment numbers avoid it, and products are rarely sold in sets of four. Buildings in East Asia sometimes skip every floor with a 4 in it, so a "50th floor" may be far lower than fifty storeys up.

Eight: prosperity in China

The flip side of four is 8, considered the luckiest number in Chinese culture. Again it's a homophone: 八 (bā, "eight") sounds like 發 (fā), as in fācái, "to become wealthy". People pay large premiums for phone numbers, licence plates, and addresses stuffed with eights. The most famous example: the 2008 Beijing Olympics opened at 8 seconds past 8:08 pm on 8 August 2008 (08/08/08) — a date chosen deliberately for its cascade of eights.

Thirteen, and the fear of Friday

In the West, 13 is the classic unlucky number, with a name to match: triskaidekaphobia. Many hotels and tall buildings have no 13th floor (the lift jumps from 12 to 14), airlines skip row 13, and some people won't sit thirteen to a table — a superstition often traced to the Last Supper, at which thirteen were present. When the 13th of a month falls on a Friday, the dread compounds into friggatriskaidekaphobia; Friday the 13th has been treated as unlucky in Western folklore for centuries and became a pop-culture fixture in the 20th.

The rest of the world's superstitions

3 — lucky and "complete" across many Western cultures: the rule of three, three wishes, "third time's the charm", the Holy Trinity.
9 — auspicious in China (it sounds like "long-lasting" and was the emperor's number), but avoided in Japan, where ku also means "suffering" or "agony".
17 — the unlucky number in Italy: the Roman numeral XVII can be rearranged into VIXI, Latin for "I have lived" — i.e., "I am dead". Some Italian planes and hotels skip row 17 the way others skip 13.
666 — the "number of the beast" from the Book of Revelation, shorthand for evil in Western culture (and the source of its own phobia, hexakosioihexekontahexaphobia).
5 — associated with the five elements and generally positive in Chinese thought, and a protective number in several traditions (the hamsa, the five pillars).

Why numbers get these meanings

Two forces do most of the work. The first is homophony: in tonal, character-based languages like Chinese, a number that sounds like a lucky or unlucky word inherits its fortune — which is why the same digit can be lucky in one country and unlucky in another. The second is religion and folklore: seven and three are baked into scripture and story; thirteen carries the shadow of the Last Supper. Layered on top is plain repetition — once a belief is common enough that developers skip the 13th floor, the absence itself keeps the superstition alive.

None of it changes the mathematics. But the meanings are real in the sense that matters: they shape how people build, buy, marry, and count.

On NumberWiki

Numbers with a documented cultural belief carry a Cultural significance section on their page, tagged as lucky, unlucky, sacred, or slang. Browse the lucky numbers and unlucky numbers the site tracks, or jump straight to 4, 7, 8, 13, or 666 to see the beliefs in context.