Nodejs Utililty Methods Number to Readable Format

Number.prototype.humanize = function(rounding, delimiter, separator) {
    rounding = (typeof rounding != 'undefined') ?  rounding : 2;
    delimiter = (typeof delimiter != 'undefined') ? delimiter : ',';
    separator = (typeof separator != 'undefined') ? separator : '.';
    var value = (function(value) {
        if (rounding == 0) return Math.round(value);
        var round_by = Math.pow(10, rounding);
        return (Math.round(value * (round_by)) / round_by);
    })(this);
...

Number.prototype.toThousands = function() {
  return (this / 1000).toFixed(1) + 'K';
};

Number.prototype.byteFormat = function(){
  var str = ""
  if(this < 1024){
    str = this + "??"
  } else if(this < 1024*2014){
    str = (this/1024).toFixed(1) + "KB"
  } else{
    str = this/(1024*1024).toFixed(1) + "MB"
  return str

Number.prototype.bytesToHuman = function () {
  return (this/(1000*1000)).toFixed(2) + 'Mb';
};

Number.prototype.bytesToSize = function() {
  var bytes = this;
  var k = 1024;
  var sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
  if (bytes == 0) return '0 Bytes';
  var i = parseInt(Math.floor(Math.log(bytes) / Math.log(k)),10);
  return (bytes / Math.pow(k, i)).toPrecision(3) + ' ' + sizes[i];
};