Having this address: https://etherscan.io/address/0x7cB57B5A97eAbe94205C07890BE4c1aD31E486A8
The balance on the web is 21.76252288478066826 Ether
But using the API the balance is: https://ropsten.etherscan.io/api?apikey=GY9KKYEJF1HDEPIAIRGA66R2RIQWQXV9UZ&module=account&action=balance&address=0x7cB57B5A97eAbe94205C07890BE4c1aD31E486A8&tag=latest
5000014636180791194320764
I don't even know what unit is that. Because the documentation don't say anything.