File readable by only PHP?

I’d like to make a file on my server be readable by PHP, but not directly accessible with a browser. Say my Apache installation’s root is /apache. I’d like PHP to be able to get the text of /apache/1.txt, but not allow the user to go to domain.tld/1.txt and view the contents. I’d still like to be able to read/write the file through FTP/SFTP without root.

What would be the propper chmod string for this? 642 seems likely, but I’m not sure how PHP accesses the file.

Redirect all request coming to /1.txt to something else using .htaccess or apache configuration. So, if some one will try to access domain.tld/1.txt, it will redirect.

EDIT

Example:

suku@ubuntu-vm:/var/www/html$ grep info.php /etc/apache2/sites-available/default
        RedirectMatch ^/info.php /html/index.htmlsuku@ubuntu-vm:/var/www/html$ sudo cat ../info.php 
<?php
phpinfo();
?>suku@ubuntu-vm:/var/www/html$ cat index.html 
You redirected to here becuase you tried to access localhost/info.php
suku@ubuntu-vm:/var/www/html$ pwd
/var/www/htmlsuku@ubuntu-vm:/var/www/html$ links http://localhost/info.php -dump
You redirected to here becuase you tried to access localhost/info.phpsuku@ubuntu-vm:/var/www/html$ cd ..
suku@ubuntu-vm:/var/www$ ls -l info.php 
-rw-r----- 1 www-data www-data 20 Jan 12 11:25 info.php

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