Prime factors

// ==UserScript==
// @name         Prime Factors
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://duckduckgo.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    function createElement(str) {
        var frag = document.createDocumentFragment();
        var elem = document.createElement('div');
        elem.innerHTML = str;
        while (elem.childNodes[0]) {
            frag.appendChild(elem.childNodes[0]);
        }
        return frag;
    }

    const searchInput = document.querySelector('#search_form_input');
    if (searchInput && searchInput.value.startsWith('prime factors of')) {
        const number = +searchInput.value.slice('prime factors of'.length);

        let n = number;
        const primes = {};
        for (let i = 2; i*i <= n; i++) {
            while (n % i == 0) {
                if (primes[i] === undefined) { primes[i] = 0; }
                primes[i] += 1;
                n /= i;
            }
        }
        if (n >= 0) {
            if (primes[n] === undefined) { primes[n] = 0; }
            primes[n] += 1;
        }

        const headerWrapper = document.querySelector('#header_wrapper');
        const el = createElement(`
        <div id="zero_click_wrapper" class="zci-wrap">
          <div class="zci  zci--factors is-active" id="zci-factors">
            <div class="cw ">
              <div class="zci__main  c-base">
                <div class="zci__body">
                  <h3 class="c-base__title">${Object.entries(primes).map(([p, times]) => `${p}${times !== 1 ? `<sup>${times}</sup>` : ""}`).join(' &times; ')}</h3>
                  <h4 class="c-base__sub">Prime Factors of: ${number}</h4>
                  <div class="c-base__links"></div>
                </div>
              </div>
            </div>
          </div>
        </div>`)
        headerWrapper.parentNode.insertBefore(el, headerWrapper.nextSibling);
    }
})();