I see two options here
var link = $('a').attr('href');
var equalPosition = link.indexOf('='); //Get the position of '='
var number = link.substring(equalPosition + 1); //Split the string and get the number.
I dont know if you're gonna use it for paging and have the text in the <a>-tag as you have it, but if you should you can also do
var number = $('a').text();