0
0 is even.
Zero is the additive identity of the integers. It is neither positive nor negative, and is the only integer that is neither prime nor composite. The Babylonians used a placeholder for zero by 300 BCE, but its treatment as a true number is generally credited to Indian mathematicians, with Brahmagupta giving the first explicit rules for arithmetic with zero in 628 CE.
Interestingness
Properties
Representations
- In words
- zero
- Ordinal
- 0th
- Binary
- 0
- Octal
- 0
- Hexadecimal
- 0x0
- Base64
- AA==
- One's complement
- 255 (8-bit)
Historical numeral systems
- Mayan (base 20)
- 𝋠
- Chinese
- 零
- Chinese (financial)
- 零
Also seen as
As an ASCII codepoint, 0 is NUL (null). ASCII control character.
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.0.
- Address
- 0.0.0.0
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.0
Unspecified address (0.0.0.0/8) — "this network" placeholder.
As a geographic coordinate in degrees, this matches:
- Equator (latitude) — 0° latitude — the equator divides the Earth into the Northern and Southern hemispheres.
- Prime Meridian (longitude) — 0° longitude — passes through the Royal Observatory at Greenwich, London; the reference for UTC.
As a MIDI note number, 0 is C-1 (8.2 Hz at concert pitch) — the lowest defined MIDI note. (below the ~20 Hz floor of human hearing — likely inaudible)
0 °C is the freezing point of water, and 0 K is absolute zero — the lowest temperature physically possible.
Related reading
- Fibonacci numbers — The sequence where each term is the sum of the two before it — and why it turns up everywhere.
- Triangular numbers — 1, 3, 6, 10, 15 … the counting numbers stacked into triangles, and Gauss's famous shortcut for summing them.
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.