I didn't get a message telling me h34 had posted for 51 while I was writing up my post, so I'll leave it, since our languages don't overlap, and post again for 52.
51
五十一 (ごじゅういち)

limapuluh satu

kanalimakūmākahi

ashdladiin dóó baʼąą tʼááłáʼí

naanimidana-ashi-bezhig

cincuenta y uno

cinquanta-u

cinquante et un

hanner cant ac un; pum deg un

unan hag hanter-kant

aon air leth-cheud; dà fhichead 's a h-aon deug; caogad ’s a h-aon*

caoga a haon

एकपञ्चाशत्
ekapanchaashat
femtioett
*those are just the three most common ways to say 51 in Scottish Gaelic. There are other possible ways that aren’t as much part of common usage but still grammatically correct. It’s just with 51 through 59, Scottish Gaelic goes a little nuts with possibilities. It gets nuts when you get close to 100 too, with constructions like "ceud ach dhà" which literally translates as "hundred but (minus) two," for 98, in additional to expected vigesimal and decimal forms.