FunWithNumbers (version 1.2)

harshad: Find Harshad Numbers ~~

Description

This function tests whether the input is a Harshad number in the specified base. If the input divided by the sum of the digits (in the base) is an integer, then it is a Harshad number.

Usage

harshad(x, base = 10)

Value

A single item equal to one if the input is Harshad and equal to zero if not.

Arguments

x

The integer, bigz or character string representing the integer to test.

base

The base of the input x . Bases 2 through 36 are supported.

Author

Carl Witthoft,

Details

The harshad sequence follows simple rules: Take the digits of a number in the specified base and sum them. Divide the input value by that sum. If the result is an integer, i.e. the sum divides the input, it's a Harshad number.

References

https://en.wikipedia.org/wiki/Harshad_number

Examples

harshad(20)
# [1] 1
# 2 + 0 = 2, divides  20
harshad(37,base = 8)
#[1] 0
# 3 + 7 = 12 base8 , does not divide 37 base8 (in base 10, 10 does not divide 31)