Number

1

1 — One

1 is odd, a calendar year.

One is the multiplicative identity. It is the only positive integer that is neither prime nor composite, and is the first and second number in the Fibonacci sequence.

Sources https://en.wikipedia.org/wiki/1

Catalan Number Curated Deficient Number Factorial Fibonacci Happy Number Harshad / Niven Heptagonal Hexagonal Kaprekar Number Lucas Narcissistic / Armstrong Octagonal Pentagonal Perfect Cube Perfect Square Power of Ten Power of Two Repunit Strobogrammatic Triangular

Properties

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

Divisors & multiples

All divisors (1)

Aliquot sum (sum of proper divisors): 0

Factor pairs (a × b = 1)

1 × 1

First multiples

1 · 2 · 3 · 4 · 5 · 6 · 7 · 8 · 9 · 10

Representations

In words: one
Ordinal: 1st
Roman numeral: I
Binary: 1
Octal: 1
Hexadecimal: 1

Also seen as

ASCII character

As an ASCII codepoint, 1 is control character (0x01). ASCII control character.

Hex color

#000001

RGB(0, 0, 1)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.1.