number.wiki
Number

11

11 is a prime, odd, a calendar year.

Cousin Prime Deficient Number Lucas Palindrome Prime Repdigit Repunit Sexy Prime Squarefree Strobogrammatic Twin Prime Year

Properties

Parity
Odd
Digit count
2
Digit sum
2
Digital root
2
Palindrome
Yes
Divisor count
2
σ(n) — sum of divisors
12

Primality

11 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 11
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 11)
1 × 11
First multiples
11 · 22 · 33 · 44 · 55 · 66 · 77 · 88 · 99 · 110

Representations

In words
eleven
Ordinal
11th
Roman numeral
XI
Binary
1011
Octal
13
Hexadecimal
B

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 7 (gap of 4)
  • Next prime: 13 (gap of 2)

Pair status: twin with 13, cousin with 7.

ASCII character

As an ASCII codepoint, 11 is VT (vertical tab). ASCII control character.

Hex color
#00000B
RGB(0, 0, 11)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.11.