View the PDF file Size In Post

I am trying to get Attachment file URL and File size in wordpress post. Here by the given loop i am get the file URl but how to Get the file size . Tell me about the loop for attachment file size.

`<?php
// Get all PDFs that are attached to this post in the loop
$pdf_attachments = get_attached_media(‘application/pdf’, get_the_ID());

// Pull out the first attached PDF (even if there’s only one, the above returns an array)
$pdf_attachment = key($pdf_attachments);

// Get the link to the PDF
$pdf_link = wp_get_attachment_url($pdf_attachment);
?>

in Post:
<?php echo $pdf_link ?>