A septemvigesimal numeral system

Numeral system

A numeral system is a writing system for expressing numbers, that is a mathematical notation for representing numbers of a given set, using graphemes or symbols in a consistent manner....

 has a base of twenty-seven

Twenty-Seven

Twenty-Seven is the fifth studio album by The Adicts. It was originally released by Cleopatra Records in the USA in 1992. It was re-released by Anagram Records in 1993 and 1997, Captain Oi! Records in 2002 and by SOS Records in 2006, each with bonus tracks....

. It is used in two natural language

Natural language

In the philosophy of language, a natural language is any language which arises in an unpremeditated fashion as the result of the innate facility for language possessed by the human intellect. A natural language is typically used for communication, and may be spoken, signed, or written...

s, the Telefol language

Telefol language

Telefol is a language spoken by the Telefol people in Papua New Guinea, notable for possessing a base-27 numeral system.-History:The Iligimin people also spoke Telefol, but they were defeated by the Telefol proper.-Orthography:...

 and the Oksapmin language

Oksapmin language

Oksapmin is a Trans–New Guinea language spoken in Telefomin District, Sandaun, Papua New Guinea. It has been influenced by the Ok languages , and the similarities with those languages were attributed to borrowing in the classifications of both Stephen Wurm and Malcolm Ross , where Oksapmin was...

 of Papua New Guinea

Papua New Guinea

Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...

.

Septemvigesimal notation can be used as a concise representation of ternary

Ternary numeral system

Ternary is the base- numeral system. Analogous to a bit, a ternary digit is a trit . One trit contains \log_2 3 bits of information...

 data, where each septemvigesimal digit represents three ternary digits. This is similar to using octal

Octal

The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary digits into groups of three...

 notation to represent binary

Binary numeral system

The binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2...

 data, though the digit set is closer in size to hexadecimal

Hexadecimal

In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...

.

Examples: (Digits 10–26 are represented by letters A through Q.)

Decimal	Ternary	Septemvigesimal
0	000	0
1	001	1
2	002	2
3	010	3
5	012	5
10	101	A
15	120	F
20	202	K
25	221	P
26	222	Q
27	1000	10
81	10000	30

An alternate encoding, mapping 0 to space and 1–26 to A–Z, is occasionally used in puzzles to transform ternary triplets into words or messages.