What means Nanfu? (Characters identified: 阿難)
first of all, read from right to left.
the right character, the left component is (阜, ⻖) is easy to recognise. the right component is a 口 (mouth) with surrounding stroke, so, it’s also easy to guess that it’s 阿 (u+963f)
then, confirm the guess with 漢語多功能字庫
http://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?word=阿
the left character, well, it’s also “easy” to find that it’s 難 (u+96e3)
http://humanum.arts.cuhk.edu.hk/Lexis/lexi-mf/search.php?word=難
put them together, the word is “阿難” ananda, one of the ten principle disciple of buddha.
further, judging from the photo provided, i think the characters are inscribed on a stone plinth, of a statue; that’s why i ask in the comment.
have fun :)