Smallest common multiple. Just another solution

Hi campers!
This challenge took me a lot of time, but at the end I can solve it, with probably the worst possible algorithm … but it works! I applied the fundamental theorem of arithmetics. What do you think about this approach?

Here is my code:

function smallestCommons(arr) {
  var arr1 = [];
  var arr2 = [];
  var arr3 = [];
  var temp =[];
  var prim = [];
  var primExp = [];
  var lcm;

  //fill the array between the two given values
  for(var i=Math.max(arr[0], arr[1]); i>=Math.min(arr[0], arr[1]); i--){
    arr1.push(i);
  }
  
  
  //create an array with all the prime numbers between arr.max and arr.min
  for(var p=0; p<=Math.max(arr[0], arr[1])+1; p++){
    temp.push(p);
    for(var w=2; w<=Math.sqrt(p); w++) {
      if(p!==w && p%w ===0){
         delete temp[p];
         delete temp[1];
         prim = temp.filter(Boolean).reverse();
      }
    }
  }
  
  //apply the Fundamental theorem of arithmetic (prime factorization)
  for(var j in arr1){
    for(var k in prim) {
      while(arr1[j]%prim[k] === 0){
        arr1[j] = arr1[j]/prim[k];
        arr2.push(prim[k]);  
      }  
    } 
  }

  
// Get the count of the longest repeating streak of each prime within arr2
function highestPow(value, character) {
  var count = 0;
  var maximum = 0;
  var expected;
  var index;
 
  expected = index = value.indexOf(character);

  while (index !== -1) {
    count++;

    if (index === expected) {
      if (count > maximum) {
        maximum = count;
      }
    } else {
      count = 1;
    }

    expected = index + 1;
    index = value.indexOf(character, expected);
  }

  return maximum;
}

  //create an array with the highest power of each prime number
for(var hp=1; hp<=arr2[0]; hp++){
  
  a = Math.pow(hp, highestPow(arr2, hp));
  arr3.push(a);
  
}
//multiply the highest power of each prime number together to obtain the lcm
lcm = arr3.join(',').split(',').reduce(function(a,b){return a*b;});
  console.log(lcm);
  return lcm;
}

smallestCommons([23,18]);