Number

257

257 is a prime, odd, a calendar year.

Arithmetic Number Ascending Digits Balanced Prime Chen Prime Deficient Number Evil Number Fermat Number Pernicious Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Squarefree Year

Historical context — 257 AD

Calendar year

Year 257 (CCLVII) was a common year starting on Thursday of the Julian calendar.

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Historical context — 257 BC

Calendar year

Year 257 BC was a year of the pre-Julian Roman calendar.

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Year facts

Year type: Common year
Standard 365-day year; not divisible by 4 (or divisible by 100 but not 400).
Days in year: 365
ISO weeks: 53
Long year: contains 53 ISO weeks.
Started on: Thursday
January 1, 257
Ended on: Thursday
December 31, 257
Friday the 13ths: 3
3 Friday the 13ths this year.
Decade: 250s
250–259
Century: 3rd century
201–300
Millennium: 1st millennium
1–1000
Years ago: 1,769
1769 years before 2026.

In other calendars

Hebrew: 4017 / 4018 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Fire zodiac:Ox
Sexagenary cycle position 14 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 800 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 249 / 250 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 179 / 178 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 3
Digit sum: 14
Digit product: 70
Digital root: 5
Palindrome: No
Bit width: 9 bits
Reversed: 752
Recamán's sequence: a(193) = 257
Square (n²): 66,049
Cube (n³): 16,974,593
Divisor count: 2
σ(n) — sum of divisors: 258
φ(n) — Euler's totient: 256

Primality

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

Divisors & multiples

All divisors (2)

1 · 257

Aliquot sum (sum of proper divisors): 1

Factor pairs (a × b = 257)

1 × 257

First multiples

257 · 514 (double) · 771 · 1,028 · 1,285 · 1,542 · 1,799 · 2,056 · 2,313 · 2,570

Sums & aliquot sequence

As a sum of two squares: 1² + 16²

As consecutive integers: 128 + 129

Representations

In words: two hundred fifty-seven
Ordinal: 257th
Roman numeral: CCLVII
Binary: 100000001
Octal: 401
Hexadecimal: 0x101
Base64: AQE=
One's complement: 65,278 (16-bit)

In other bases

ternary (3) 100112

quaternary (4) 10001

quinary (5) 2012

senary (6) 1105

septenary (7) 515

nonary (9) 315

undecimal (11) 214

duodecimal (12) 195

tridecimal (13) 16a

tetradecimal (14) 145

pentadecimal (15) 122

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): σνζʹ
Mayan (base 20): 𝋬·𝋱
Chinese: 二百五十七
Chinese (financial): 貳佰伍拾柒

In other modern scripts

Eastern Arabic ٢٥٧ Devanagari २५७ Bengali ২৫৭ Tamil ௨௫௭ Thai ๒๕๗ Tibetan ༢༥༧ Khmer ២៥៧ Lao ໒໕໗ Burmese ၂၅၇

Digit at this position in famous constants

π — Pi (π): Digit 257 = 5
e — Euler's number (e): Digit 257 = 8
φ — Golden ratio (φ): Digit 257 = 4
√2 — Pythagoras's (√2): Digit 257 = 3
ln 2 — Natural log of 2: Digit 257 = 9
γ — Euler-Mascheroni (γ): Digit 257 = 7

Also seen as

Prime neighborhood

Adjacent primes:

Previous prime: 251 (gap of 6)
Next prime: 263 (gap of 6)

Pair status: sexy with 251, sexy with 263.

Unicode codepoint

Latin Small Letter A With Macron

U+0101

Lowercase letter (Ll)

UTF-8 encoding: C4 81 (2 bytes).

Lookup U+0101 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000101

RGB(0, 1, 1)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.1.

Address: 0.0.1.1
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.1.1

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