Primecoin Primecoin logo Denominations Subunit 0.001 mXPM (millicoin) 0.000001 μXPM (microcoin) 0.00000001 Smallest unit Plural Primecoin, primecoins Symbol Ψ Nickname XPM Demographics Date of introduction 7 July 2013[1] User(s) International Issuance Central bank None, the primecoin peer-to-peer network regulates and distributes through consensus in protocol.[citation needed] Valuation Inflation Limited release, production rate before this limit re-evaluated with the production of every block (at a rate of approximately 1 block per minute) based on the difficulty with which primecoins are produced.[citation needed]