Number
128
128 is a composite number, even, a calendar year.
Properties
- Parity
- Even
- Digit count
- 3
- Digit sum
- 11
- Digital root
- 2
- Palindrome
- No
- Divisor count
- 8
- σ(n) — sum of divisors
- 255
Primality
Prime factorization: 2 7
Divisors & multiples
Aliquot sum (sum of proper divisors):
127
Representations
- In words
- one hundred twenty-eight
- Ordinal
- 128th
- Roman numeral
- CXXVIII
- Binary
- 10000000
- Octal
- 200
- Hexadecimal
- 80
Also seen as
Goldbach decomposition
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 128, here are decompositions:
- 19 + 109 = 128
- 31 + 97 = 128
- 61 + 67 = 128
Unicode codepoint
U+0080
Control character (Cc)
UTF-8 encoding: C2 80 (2 bytes).
Hex color
#000080
RGB(0, 0, 128)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.128.