Number analysis
27
27 is a composite odd number that factors as 3^3.
27 is a composite odd number that factors as 3^3.
The number itself
- Value
- 27
- Digits
- 2
- Digit sum
- 9
- Reversed
- 72
- Palindrome
- No
2 + 7
Digit sum repeated until one digit remains; equals n mod 9 (with 9 for multiples of 9).
Reverses to 72.
Parity and primality
- Parity
- Odd
- Prime
- No
- Squarefree
- No
- Prime power
- 3^3
- Powerful
- Yes
- Möbius μ(n)
- 0
- Nearest primes
- 23 ← → 29
Leaves remainder 1 on division by 2.
Composite — it factors as 3^3.
1 distinct prime factor, 3 with multiplicity.
At least one prime appears squared.
A single prime raised to a power.
Every prime factor appears at least squared.
Zero, because a squared prime divides n.
A gap of 6 between them.
Divisors
- Aliquot sum
- 13
- Classification
- Deficient
1, 3, 9, 27
The proper divisors — everything except n itself.
Its proper divisors fall short by 14.
How many integers from 1 to n share no factor with n.
Sums and additive structure
- Sum of two squares
- No
- Sum of three squares
- Yes
- Sum of four squares
- Yes
- Sum of two cubes
- 0³ + 3³
A prime congruent to 3 mod 4 divides it an odd number of times, which rules it out.
Legendre's three-square theorem allows it.
Lagrange's four-square theorem: every non-negative integer is, without exception.
Shapes and sequences
- Perfect cube
- Yes — 3³
Digit curiosities
- Happy number
- No
- Harshad number
- Yes
- Collatz trajectory
- 111 steps to 1
Summing the squares of its digits falls into the 4 → 16 → 37 → … → 4 cycle.
Divisible by its digit sum 9 — 27 ÷ 9 = 3.
Peaks at 9,232 along the way.
Written other ways
- Binary
- 11011
- Octal
- 33
- Hexadecimal
- 1B
- Base 36
- R
- Roman numerals
- XXVII
- In words
- twenty-seven
- Scientific notation
- 2.7 × 10^1
Is 27 a prime number?
Composite — it factors as 3^3.
Nearby numbers
Other numeral systems
Beyond the bases and Roman numerals above, these notations write 27 their own way.
- Greek (alphabetic)
- ΚΖʹ
- Babylonian cuneiform
- 𒎙𒐛
- Tamil
- ௨௰௭
References
Further reading: Wikipedia · Wikidata
Notations, naming and the links above come from Wikidata, whose structured data is dedicated to the public domain under CC0-1.0. Retrieved 2026-10-07.