Regex: как ограничить максимальное количество целых чисел в буквенно-цифровом поле

//use 'keydown' to prevent copy pasting invalid values
var inputLength = 0;
$('#invoice').on('keydown', function(){inputLength = $(this).val().length});
//check against criteria set upon input
$('#invoice').on('keyup', function(){
  if ($(this).val().length>60 || $(this).val().match(/[0-9]/g).length>15 || $(this).val().match(/[^\w^0-9]/)){
    $(this).val($(this).val().slice(0,inputLength-$(this).val().length));
  }
});

<script src = "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input id = "invoice"></input>

function limit( str ) {
  var patt = /[~`!@#\$%\^&\*()_\+ = {}\[\]\|\;\"\'\,\<\>\?]/g;
  var strWithoutSpecialChars = str.replace(patt,'') ;
  var count = 0, result = '', numberDigit = 0 ;
  for (var i = 0; i < strWithoutSpecialChars.length && count < 60; i++ ) {
    var ch = strWithoutSpecialChars[i] ;
    if ( /\d/.test(ch) ) {
      numberDigit++;
      if ( numberDigit < 15 ) { result += ch; count++ ; }
      else { continue ; }
    }
    else { result += ch; count++ ; }
  }
 return result ;
}

var longText = 'Miusov, 5699999999as a man man of breeding and 555deilcacy, could 98955not but feel some inwrd qualms, when he reached the Father Superiors with Ivan: he felt ashamed of havin lost his temper. He felt that he ought to have disdaimed that despicable wretch, Fyodor Pavlovitch, too much to have been upset by him in Father Zossimas cell, and so to have forgotten himself. "Teh monks were not to blame, in any case," he reflceted, on the steps. "And if theyre decent people here (and the Father Superior, I understand, is a nobleman) why not be friendly and courteous withthem? I wont argue, Ill fall in with everything, Ill win them by politness, and show them that Ive nothing to do with that Aesop, thta buffoon, that Pierrot, and have merely been takken in over this affair, just as they have.';

var result = limit(longText) ;
console.info('Length : ' + result.length ) ;
console.info( 'String : ' + result ) ;