Odd and even numbers in Chinese

I don't often need to know the words for odd and even in Chinese, but I finally decided to try to commit them to memory. It took me a bit of effort to find a mnemonic that would help me remember which was which:

• odd number 奇數 jī shù
• even number 偶數 ǒu shù

First I was hoping that the Pinyin letters, e.g., that the number of letters in one (ideally in "odd") would actually be odd and the other even. No such luck there, since they're both two letters.

Then I hoped that the Pinyin tone would be odd (ideally in "odd") would be an odd number and the other even. Again, no such luck, since they're first and third.

Finally I realized that the character for odd (referring to number) is also the character for strange/odd (which is, however, pronounced differently, as qí), and I had my mnemonic.