number.wiki
Number

9

9 is a composite number, odd, a calendar year.

Deficient Number Harshad / Niven Kaprekar Number Narcissistic / Armstrong Perfect Square Powerful Number Year

Properties

Parity
Odd
Digit count
1
Digit sum
9
Digital root
9
Palindrome
Yes
Divisor count
3
σ(n) — sum of divisors
13

Primality

Prime factorization: 3 2

Divisors & multiples

All divisors (3)
1 · 3 · 9
Aliquot sum (sum of proper divisors): 4
Factor pairs (a × b = 9)
1 × 9
3 × 3
First multiples
9 · 18 · 27 · 36 · 45 · 54 · 63 · 72 · 81 · 90

Representations

In words
nine
Ordinal
9th
Roman numeral
IX
Binary
1001
Octal
11
Hexadecimal
9

Also seen as

ASCII character

As an ASCII codepoint, 9 is HT (horizontal tab). ASCII control character.

Hex color
#000009
RGB(0, 0, 9)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.9.