Simple fraction to mixed number converter

mixed-number-converter.js

// https://www.codewars.com/kata/simple-fraction-to-mixed-number-converter/
var greatest = (a,b) => (b===0) ? a : greatest(b,a%b)
function mixedFraction(s){
  arr = s.split('/')
  dividend = Number(arr[0])
  divisor = Number(arr[1])
  if(divisor === 0){
  throw "ZeroDivisionError";
  } else {
    if(dividend%divisor === 0){
    return (dividend/divisor).toString()
  } else {
      whole = (dividend/divisor) | 0;
      numerator = dividend%divisor
      denominator = Number(divisor)
      common = greatest(numerator,denominator)
      fnumerator = numerator/common
      fdenominator = denominator/common
    if(Math.abs(dividend) < Math.abs(divisor)){
      if(fdenominator < 0){fdenominator = fdenominator * -1; fnumerator = fnumerator * -1}
      return fnumerator.toString()+'/'+fdenominator.toString()
    } else {           
      return whole + " " + Math.abs(fnumerator).toString() + "/" + Math.abs(fdenominator).toString()
    }
  }
  }
}