title: Renaming files with adding a number to filename in bash
body: <p>I have lots of file like these:</p>
  
  <pre><code>13831_1.jpg
  13838_1.jpg
  138035_1.jpg
  138037_1.jpg
  138039_1.jpg
  </code></pre>
  
  <p>I need to add a value of 5000000 to the numbers of the filenames. 
  The result should be the following:</p>
  
  <pre><code>5013831_1.jpg
  5013838_1.jpg
  5138035_1.jpg
  5138037_1.jpg
  5138039_1.jpg
  </code></pre>
  
  <p>Is there a way to do it with bash or perl?</p>