# 1728 (number)

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 ← 1727 1728 1729 →
Cardinal one thousand seven hundred twenty-eight
Ordinal 1728th
(one thousand seven hundred and twenty-eighth)
Factorization 26× 33
Roman numeral MDCCXXVIII
Binary 110110000002
Ternary 21010003
Quaternary 1230004
Quinary 234035
Senary 120006
Octal 33008
Duodecimal 100012
Hexadecimal 6C016
Vigesimal 46820
Base 36 1C036

1728 is the natural number following 1727 and preceding 1729. 1728 is a dozen gross, one great gross (or grand gross, or, in Germanic, Mass).

## In mathematics

It is the cube of 12 and, as such, is important in the duodecimal number system. It is the number of cubic inches in a cubic foot. 1728 occurs in the algebraic formula for the j-invariant of an elliptic curve. As a consequence, it is sometimes called a Zagier as a pun on the Gross–Zagier theorem. The number 1728 is one less than the Ramanujan Number 1729.

• 1728 = 123
• 1728 = 33 × 43
• 1728 = 23 × 63
• 1728 = 63 + 83 + 103
• 1728 = 242 + 242 + 242