JSFiddle - React, Tailwind, and code Playground

JavaScript

var numb = "5136789431235";
var res = [];
for (var i = 0, len = numb.length; i < len-1; i++) {
  if (numb[i] < numb[i+1]) res.push(new Array(numb[i],numb[i+1]))
}
res.forEach(function(k){console.log(k)});