20 characters in the Sinhala Archaic Numbers Unicode block.
U+111E1SINHALA ARCHAIC DIGIT ONEU+111E2SINHALA ARCHAIC DIGIT TWOU+111E3SINHALA ARCHAIC DIGIT THREEU+111E4SINHALA ARCHAIC DIGIT FOURU+111E5SINHALA ARCHAIC DIGIT FIVEU+111E6SINHALA ARCHAIC DIGIT SIXU+111E7SINHALA ARCHAIC DIGIT SEVENU+111E8SINHALA ARCHAIC DIGIT EIGHTU+111E9SINHALA ARCHAIC DIGIT NINEU+111EASINHALA ARCHAIC NUMBER TENU+111EBSINHALA ARCHAIC NUMBER TWENTYU+111ECSINHALA ARCHAIC NUMBER THIRTYU+111EDSINHALA ARCHAIC NUMBER FORTYU+111EESINHALA ARCHAIC NUMBER FIFTYU+111EFSINHALA ARCHAIC NUMBER SIXTYU+111F0SINHALA ARCHAIC NUMBER SEVENTYU+111F1SINHALA ARCHAIC NUMBER EIGHTYU+111F2SINHALA ARCHAIC NUMBER NINETYU+111F3SINHALA ARCHAIC NUMBER ONE HUNDREDU+111F4SINHALA ARCHAIC NUMBER ONE THOUSAND