Harshad number

In recreational mathematics, a harshad number (or Niven number) in a given number base, is an integer that is divisible by the sum of its digits when written in that base. Harshad numbers in base ${\displaystyle n}$ are also known as ${\displaystyle n}$-harshad (or ${\displaystyle n}$-Niven) numbers. Harshad numbers were defined by D. R. Kaprekar, a mathematician from India. The word "harshad" comes from the Sanskrit harṣa (joy) + da (give), meaning joy-giver. The term “Niven number” arose from a paper delivered by Ivan M. Niven at a conference on number theory in 1977. All integers between zero and ${\displaystyle n}$ are ${\displaystyle n}$-harshad numbers.

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