U can use this method as well -
const arrayOfDigits = Array.from(String(num), Number);

here, Array.from() creates a new array from the array-like object, by passing String(num), we convert the number into a string, which splits it into its individual characters
the second parameter, Number, is a callback that converts each character back into a digit, creating an array of digits from the number

i think so yes

reducer can take up to 4 arguments, you can just omit the last two, which are indices and array. So you can use acc and value of the index.

is this solution considered any good?