Number
20
20 is a composite number, even, a calendar year.
Properties
- Parity
- Even
- Digit count
- 2
- Digit sum
- 2
- Digital root
- 2
- Palindrome
- No
- Divisor count
- 6
- σ(n) — sum of divisors
- 42
Primality
Prime factorization: 2 2 × 5
Divisors & multiples
Aliquot sum (sum of proper divisors):
22
Representations
- In words
- twenty
- Ordinal
- 20th
- Roman numeral
- XX
- Binary
- 10100
- Octal
- 24
- Hexadecimal
- 14
Also seen as
Goldbach decomposition
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 20, here are decompositions:
- 3 + 17 = 20
- 7 + 13 = 20
ASCII character
As an ASCII codepoint, 20 is control character (0x14). ASCII control character.
Network port
TCP/UDP port 20 is the well-known port for FTP-DATA — File Transfer Protocol — data channel.
Hex color
#000014
RGB(0, 0, 20)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.20.