20 characters in the Kaktovik Numerals Unicode block.
U+1D2C0KAKTOVIK NUMERAL ZEROU+1D2C1KAKTOVIK NUMERAL ONEU+1D2C2KAKTOVIK NUMERAL TWOU+1D2C3KAKTOVIK NUMERAL THREEU+1D2C4KAKTOVIK NUMERAL FOURU+1D2C5KAKTOVIK NUMERAL FIVEU+1D2C6KAKTOVIK NUMERAL SIXU+1D2C7KAKTOVIK NUMERAL SEVENU+1D2C8KAKTOVIK NUMERAL EIGHTU+1D2C9KAKTOVIK NUMERAL NINEU+1D2CAKAKTOVIK NUMERAL TENU+1D2CBKAKTOVIK NUMERAL ELEVENU+1D2CCKAKTOVIK NUMERAL TWELVEU+1D2CDKAKTOVIK NUMERAL THIRTEENU+1D2CEKAKTOVIK NUMERAL FOURTEENU+1D2CFKAKTOVIK NUMERAL FIFTEENU+1D2D0KAKTOVIK NUMERAL SIXTEENU+1D2D1KAKTOVIK NUMERAL SEVENTEENU+1D2D2KAKTOVIK NUMERAL EIGHTEENU+1D2D3KAKTOVIK NUMERAL NINETEEN