Where does “友愛数” come from?

友愛数 (Japanese) comes from Japanese 数, from Middle Chinese 數, from Old Chinese 數.

友愛数 (Japanese): amicable numbers, two different numbers related in such a way that the sum of the proper divisors of each is equal to the other number

Definitions

  1. amicable numbers, two different numbers related in such a way that the sum of the proper divisors of each is equal to the other number

Ancestry of “友愛数”, step by step

友愛数 traces back through two separate lines of ancestry.

via Japanese

StepLanguageWordMeaning
1Japanesenumber; amount; number; several
2Middle Chinese
3Old Chinese

via Japanese 友愛

StepLanguageWordMeaning
1Japanese友愛affection, friendship, brotherhood, fraternity, friendly love, fraternal love
Every word from Old Chinese Every word from Middle Chinese Every word from Japanese