my ($count, $word);
while (<>) {
    $count++ unless /#/;        # or maybe /^#/ would be better?
    if (/^# word (\d+)/) {      # or \S+, etc. -- depending on what's a valid word
        print "word $word\nnumber of text = $count\n" if defined $word;
        $count = 0;
        $word  = $1;
    }
}
print "word $word\nnumber of text = $count\n" if defined $word;    # handle leftover word.