Recursion: Harshad Number

A number is said to be Harshad if it's exactly divisible by the sum of its digits. Create a function that determines whether a number is a Harshad or not.

Examples

isHarshad(75) ➞ false
// 7 + 5 = 12
// 75 is not exactly divisible by 12

isHarshad(171) ➞ true
// 1 + 7 + 1 = 9
// 9 exactly divides 171

isHarshad(481) ➞ true

isHarshad(89) ➞ false

isHarshad(516) ➞ true

isHarshad(200) ➞ true

Notes

• You are expected to solve this challenge via recursion.
• An iterative version of this challenge can be found via this link.
• A collection of challenges in recursion can be found via this link.