28 (number)

This article is about the number 28. For the year, see 28.

28 (twenty-eight) is a number. It comes between twenty-seven and twenty-nine. Twenty-eight is an even number. It is divisible by 1, 2, 4, 7, 14, and 28. 28 is a perfect number. The perfect number before twenty-eight is six.

← 27 28 29 →
← 20 21 22 23 24 25 26 27 28 29 → ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	twenty-eight
Ordinal	28th (twenty-eighth)
Factorization	22· 7
Roman numeral	XXVIII
Binary	111002
Ternary	10013
Quaternary	1304
Quinary	1035
Senary	446
Octal	348
Duodecimal	2412
Hexadecimal	1C16
Vigesimal	1820
Base 36	S36

28 (number) Media

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  The number 28 depicted as 28 balls arranged in a triangular pattern with the number of layers of 7

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  28 as the sum of four nonzero squares.