var id_of_div = "div_id_12";
var id_number = parseInt(id_of_div.replace(/[^0-9.]/g, ""));
console.log(id_number);//12
You can get it like this:
var suffix = 'comment_like_123456'.match(/d+/); // 123456
With respect to button:
$('.comment_like').click(function(){
var suffix = this.id.match(/d+/); // 123456
});
It works for me.