Largest Palindrome Product LeetCode solution in JavaScript

1
/**
2
 * @param {number} n
3
 * @return {number}
4
 */
5
var largestPalindrome = function (n) {
6
  if (n === 1) return 9;
7
  let hi = BigInt(Math.pow(10, n) - 1);
8
  let num = hi;
9
  while (num > 0) {
10
    num -= 1n;
11
    const palindrome = BigInt(
12
      String(num) + String(num).split("").reverse().join("")
13
    );
14
    for (let i = hi; i >= 2n; i -= 2n) {
15
      const j = palindrome / i;
16
      if (j > hi) break;
17
      if (palindrome % i === 0n) {
18
        return String(palindrome % 1337n);
19
      }
20
    }
21
  }
22
};