Compatibility summary
You will need a travel adapter in Nauru; plug types used there differ from Brazil. Voltage differs by more than 20% — a voltage converter may be needed for some appliances.
Plug comparison
Brazil plug types: C N
Nauru plug types: I
There is no common plug type between Brazil (C N) and Nauru (I). You need a travel adapter.
Voltage comparison
Brazil: 127V, 60Hz
Nauru: 240V, 50Hz
Voltage converter recommended (Brazil 127V vs Nauru 240V).