JSFiddle - React, Tailwind, and code Playground

JavaScript

function primeFactorization(num){
  var root = Math.sqrt(num),  
  result = arguments[1] || [], 
  x = 2; 
  
  if(num % x){
   x = 3;
   while((num % x) && ((x = x + 2) < root)){}
  }
  
  x = (x <= root) ? x : num;
  result.push(x);

 
  return (x === num) ? result : primeFactorization(num/x, result) ;
}

var number = prompt("Введите число", "");

alert('простые множители числа  ' + number + ' :\n ' + primeFactorization(number));