JSFiddle - React, Tailwind, and code Playground

HTML

<input value="9879879087">
<span></span>

JavaScript

function compress(n) {
  var symbols = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyzÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïð'.split('');
  var d = n;
  var compressed = '';

  while (d >= 1) {
    compressed = symbols[(d - (symbols.length * Math.floor(d / symbols.length)))] + compressed;
    d = Math.floor(d / symbols.length);
  }

  return compressed;
}

$('input').keyup(function() {
	$('span').html(compress($(this).val()))
})

$('span').html(compress($('input').val()))