You can get a list of string from your number, by converting it to a string, and then splitting it with an empty string. The result will be an array of strings, each containing a digit:
const num = 124124124
const strArr = `${num}`.split("")
OR to build on this, map each string digit and convert them to a Number
:
const intArr = `${num}`.split("").map(x => Number(x))