Number

256

256 — Two to the Eighth

256 is a composite number, even, a calendar year.

Two hundred fifty-six equals (2^8), making it the number of distinct values an unsigned 8-bit byte can represent. It is fundamental to computing.

Sources https://en.wikipedia.org/wiki/256_(number)

Ascending Digits Computing Curated Deficient Number Odious Number Perfect Square Power of Two Powerful Number Practical Number Recamán's Sequence

Historical context — 256 AD

Calendar year

Year 256 (CCLVI) was a leap year starting on Tuesday of the Julian calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

Historical context — 256 BC

Calendar year

Year 256 BC was a year of the pre-Julian Roman calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

Year facts

Year type: Leap year
Divisible by 4 and not by 100; February has 29 days.
Days in year: 366
ISO weeks: 52
Started on: Tuesday
January 1, 256
Ended on: Wednesday
December 31, 256
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 250s
250–259
Century: 3rd century
201–300
Millennium: 1st millennium
1–1000
Years ago: 1,770
1770 years before 2026.

In other calendars

Hebrew: 4016 / 4017 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Fire zodiac:Rat
Sexagenary cycle position 13 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 799 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 248 / 249 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 178 / 177 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 13
Digit product: 60
Digital root: 4
Palindrome: No
Bit width: 9 bits
Reversed: 652
Recamán's sequence: a(195) = 256
Square (n²): 65,536
Cube (n³): 16,777,216
Square root (√n): 16
Divisor count: 9
σ(n) — sum of divisors: 511
φ(n) — Euler's totient: 128
Sum of prime factors: 16

Primality

Prime factorization: 2 ⁸

Nearest primes: 251 (−5) · 257 (+1)

Divisors & multiples

All divisors (9)

1 · 2 · 4 · 8 · 16 · 32 · 64 · 128 (half) · 256

Aliquot sum (sum of proper divisors): 255

Factor pairs (a × b = 256)

1 × 256

2 × 128

4 × 64

8 × 32

16 × 16

First multiples

256 · 512 (double) · 768 · 1,024 · 1,280 · 1,536 · 1,792 · 2,048 · 2,304 · 2,560

Sums & aliquot sequence

As a sum of two squares: 0² + 16²

Aliquot sequence: 256 → 255 → 177 → 63 → 41 → 1 → 0 — terminates at zero

Representations

In words: two hundred fifty-six
Ordinal: 256th
Roman numeral: CCLVI
Binary: 100000000
Octal: 400
Hexadecimal: 0x100
Base64: AQA=
One's complement: 65,279 (16-bit)

In other bases

ternary (3) 100111

quaternary (4) 10000

quinary (5) 2011

senary (6) 1104

septenary (7) 514

nonary (9) 314

undecimal (11) 213

duodecimal (12) 194

tridecimal (13) 169

tetradecimal (14) 144

pentadecimal (15) 121

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹 𒌋𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): σνϛʹ
Mayan (base 20): 𝋬·𝋰
Chinese: 二百五十六
Chinese (financial): 貳佰伍拾陸

In other modern scripts

Eastern Arabic ٢٥٦ Devanagari २५६ Bengali ২৫৬ Tamil ௨௫௬ Thai ๒๕๖ Tibetan ༢༥༦ Khmer ២៥៦ Lao ໒໕໖ Burmese ၂၅၆

Digit at this position in famous constants

π — Pi (π): Digit 256 = 8
e — Euler's number (e): Digit 256 = 4
φ — Golden ratio (φ): Digit 256 = 4
√2 — Pythagoras's (√2): Digit 256 = 2
ln 2 — Natural log of 2: Digit 256 = 2
γ — Euler-Mascheroni (γ): Digit 256 = 3

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 256, here are decompositions:

5 + 251 = 256
17 + 239 = 256
23 + 233 = 256
29 + 227 = 256
59 + 197 = 256
83 + 173 = 256
89 + 167 = 256
107 + 149 = 256

Showing the first eight; more decompositions exist.

Unicode codepoint

Latin Capital Letter A With Macron

U+0100

Uppercase letter (Lu)

UTF-8 encoding: C4 80 (2 bytes).

Lookup U+0100 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000100

RGB(0, 1, 0)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.0.

Address: 0.0.1.0
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.1.0

Unspecified address (0.0.0.0/8) — "this network" placeholder.

NANP area code 256

The number 256 is an active NANP area code (North American Numbering Plan).

Primary area: Huntsville
Region: Alabama
Country: United States

Most NANP area codes have multiple overlays in dense regions; the primary area listed is the historic/largest population center for this code.

Look up area code 256 ↗