Number reference
27 explained.
27: twenty-seven, composite, perfect cube; factors, prime factorization, roots, binary, hexadecimal, and digit properties.
Identity and representations
- Written form
- twenty-seven
- Classification
- composite
- Factors
- 1, 3, 9, 27
- Prime factorization
- 3 × 3 × 3
- Square root
- 5.196152
- Cube root
- 3
- Binary
- 11011
- Octal
- 33
- Hexadecimal
- 1B
- Roman numeral
- XXVII
- Digit sum
- 9
- Digital root
- 9
What makes 27 notable
- Perfect cube. 27 = 3³, so a cube of edge 3 has a volume of 27.
27 in everyday use
Twenty-seven is three cubed, so a Rubik's Cube is built from 27 little cubes in a 3 × 3 × 3 block, though the centre one is hidden. It is the atomic number of cobalt. The New Testament contains 27 books, and the US Constitution has 27 amendments. The "27 Club" refers to musicians who died at that age, including Jimi Hendrix, Janis Joplin, Jim Morrison, Kurt Cobain, and Amy Winehouse.
Twenty-seven is the only two-digit cube apart from 64. Its digits add to 9, and it has a rare property: the digits of its cube, 19,683, add back up to 27 itself. It is 3 raised to the third power and also 3 raised to the power 3 — the same thing — so in ternary it is 1000. In the Collatz problem, 27 is notorious for taking 111 steps to reach 1, climbing as high as 9,232 along the way.
Nearby numbers
How to read this page
The factor list shows every way 27 splits into equal whole-number groups — 4 divisors in total. The prime factorisation is the compact form of that same information, and the base conversions restate 27 for contexts that do not use decimal.
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