-rw--r--r-- 2 kamix users 5 Nov 17:10 hardfile.txt
That's the number of hard links the file has. A "hard link" is actually between two directory entries; they're really the same file. You can tell by looking at the output from
stat hardlink.file | grep -i inode
Device: 805h/2053d Inode: 1835019 Links: 2
Notice again the number of links is 2, indicating there's another listing for this file somewhere. The reason you know this is the same file as another is they have the same inode number; no other file will have that. Unfortunately, this is the only way to find them (by inode number).
There are some ideas about how best to find a file by inode (e.g., with
find) in this Q&A.