This javascript will add absolute positioned div's with pagenumbers on the right bottom corner and works in all browsers.
A4 height = 297mm = 1123px(96dpi)
<html>
<head>
<style type="text/css">
@page {
size: A4;
margin: 0;
}
body {
margin: 0;
}
</style>
</head>
<body>
<script type="text/javascript">
window.onload = addPageNumbers;
function addPageNumbers() {
var totalPages = Math.ceil(document.body.scrollHeight / 1123); //842px A4 pageheight for 72dpi, 1123px A4 pageheight for 96dpi,
for (var i = 1; i <= totalPages; i++) {
var pageNumberDiv = document.createElement("div");
var pageNumber = document.createTextNode("Page " + i + " of " + totalPages);
pageNumberDiv.style.position = "absolute";
pageNumberDiv.style.top = "calc((" + i + " * (297mm - 0.5px)) - 40px)"; //297mm A4 pageheight; 0,5px unknown needed necessary correction value; additional wanted 40px margin from bottom(own element height included)
pageNumberDiv.style.height = "16px";
pageNumberDiv.appendChild(pageNumber);
document.body.insertBefore(pageNumberDiv, document.getElementById("content"));
pageNumberDiv.style.left = "calc(100% - (" + pageNumberDiv.offsetWidth + "px + 20px))";
}
}
</script>
<div id="content">
Lorem ipsum....
</div>
</body>
</html>