奇数(きすう)

奇数(きすう) means odd number — any integer not divisible by two (1, 3, 5, 7, etc.). The kanji 奇(き) means "strange/unusual" and 数(すう) means "number."

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 math terms

• 自然数(しぜんすう): natural number
• 整数(せいすう): integer
• 素数(そすう): prime number
• 分数(ぶんすう): fraction

Cultural note

Odd numbers are traditionally considered lucky in Japan (吉数(きっすう)). Gift money (祝儀(しゅうぎ)) is typically given in odd-numbered amounts (10,000, 30,000, 50,000 yen).