Cargar PHP en HTML

//Safe as:
index.html
number.php

//HTML:
<html>
   <head>
      <title>Home</title>
   </head>
   <body>
      <h1>Phone Number</h1>
      <?php include('number.php') ?>
   </body>
</html>

//PHP:
<?php
   echo 4895553268;
?>
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