сепаратор режима
let separator = 265264849;
console.log(separator.toString().replace(/\B(?=(\d{3})+(?!\d))/g, " "));
// " 265264894 " becomes " 265 265 894 "
Tender Tuatara
let separator = 265264849;
console.log(separator.toString().replace(/\B(?=(\d{3})+(?!\d))/g, " "));
// " 265264894 " becomes " 265 265 894 "