This is the 8989th most frequent Russian word.
рахматулла
"Рахматулла" is not originally Russian; it is an Islamic/Arabic term meaning "mercy of Allah."
In this sentence, 'Рахматулла' is used as a proper name, referring to an individual.
Рахматулла часто посещает свою семью в деревне.
Rakhmatulla often visits his family in the village.
'Рахматулла' is a proper noun here, possibly symbolizing a concept or another metaphorical usage.
Название книги звучало как 'Мир и Рахматулла'.
The title of the book sounded like 'Peace and Rakhmatulla'.
Here, 'Рахматулла' identifies a person by their name.