Number analysis
24
24 is a composite even number that factors as 2^3 × 3.
24 is a composite even number that factors as 2^3 × 3.
The number itself
- Value
- 24
- Digits
- 2
- Digit sum
- 6
- Reversed
- 42
- Palindrome
- No
2 + 4
Digit sum repeated until one digit remains; equals n mod 9 (with 9 for multiples of 9).
Reverses to 42.
Parity and primality
- Parity
- Even
- Prime
- No
- Prime factorisation
- 2^3 × 3
- Squarefree
- No
- Möbius μ(n)
- 0
- Nearest primes
- 23 ← → 29
Divisible by 2.
Composite — it factors as 2^3 × 3.
2 distinct prime factors, 4 with multiplicity.
At least one prime appears squared.
Zero, because a squared prime divides n.
A gap of 6 between them.
Divisors
- Aliquot sum
- 36
- Classification
- Abundant
1, 2, 3, 4, 6, 8, 12, 24
The proper divisors — everything except n itself.
Its proper divisors overshoot by 12.
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
- Goldbach pair
- 5 + 19
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.
The smallest pair of primes summing to n. Goldbach’s conjecture says one always exists; it remains unproven.
Shapes and sequences
- Factorial
- Yes — 4!
Digit curiosities
- Happy number
- No
- Harshad number
- Yes
- Collatz trajectory
- 10 steps to 1
Summing the squares of its digits falls into the 4 → 16 → 37 → … → 4 cycle.
Divisible by its digit sum 6 — 24 ÷ 6 = 4.
Peaks at 24 along the way.
Written other ways
- Binary
- 11000
- Octal
- 30
- Hexadecimal
- 18
- Base 36
- O
- Roman numerals
- XXIV
- In words
- twenty-four
- Scientific notation
- 2.4 × 10^1
Is 24 a prime number?
Composite — it factors as 2^3 × 3.
Nearby numbers
Other numeral systems
Beyond the bases and Roman numerals above, these notations write 24 their own way.
- Greek (alphabetic)
- ΚΔʹ
- Babylonian cuneiform
- 𒎙𒐘
- Tamil
- ௨௰௪
References
Further reading: Wikipedia · MathWorld · 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.