The rupiah (Rp) is the official currency of Indonesia. Issued and controlled by the Bank of Indonesia, the ISO 4217 currency code for the Indonesian rupiah is IDR. The name "rupiah" is derived from the Hindustani word rupiyaa (روپیہ, रुपया), ultimately from Sanskrit rupya (रूप्य; wrought silver). Informally, Indonesians also use the word "perak" ('silver' in Indonesian) in referring to rupiah. The rupiah is subdivided into 100 sen, although inflation has rendered all coins and banknotes denominated in sen obsolete.