奇 数(きすう)

きすう

noun

odd number

number

1. odd number

An integer that is not divisible by two, such as 1, 3, 5, 7, etc.

奇数(きすう)か偶数(ぐうすう)かを判定(はんてい)する。

I determine whether it's an odd or even number.

3は奇数(きすう)で、4は偶数(ぐうすう)だ。

3 is an odd number, and 4 is an even number.

奇数(きすう)の日(ひ)だけゴミを出(だ)せる。

Trash can only be put out on odd-numbered days.

Similar words

偶数(ぐうすう): even number

Common patterns

奇数(きすう)の日(ひ): odd-numbered days
奇数(きすう)月(がつ): odd-numbered months (January, March, etc.)
奇数(きすう)番号(ばんごう): odd-numbered

Related words

Cultural note

Odd numbers are traditionally considered lucky in Japan. Gift money (祝儀(しゅうぎ)) is traditionally given with an odd leading digit — 10,000, 30,000, 50,000 yen — since even overall amounts are considered inauspicious.

Etymology

奇(き) (odd, strange) + 数(すう) (number).

Related Words

Antonym: 偶数(ぐうすう) (even number)

Related: 自然数(しぜんすう) (natural number)

Related: 整数(せいすう) (integer)

Related: 素数(そすう) (prime number)

Related: 分数(ぶんすう) (fraction)

general

Added 2026.2.3 11:58 · Revised 2026.10.4 4:42

09500/09634_kisuu