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Number

285

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

Arithmetic Number Deficient Number Harshad / Niven Odious Number Pernicious Number Recamán's Sequence Sphenic Number Square Pyramidal Squarefree Year

Historical context — 285 AD

Calendar year

The year 285 (CCLXXXV) was a common year starting on Thursday of the Julian calendar.

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Historical context — 285 BC

Calendar year

Year 285 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: 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, 285
Ended on: Thursday
December 31, 285
Friday the 13ths: 3
3 Friday the 13ths this year.
Decade: 280s
280–289
Century: 3rd century
201–300
Millennium: 1st millennium
1–1000
Years ago: 1,741
1741 years before 2026.

In other calendars

Hebrew: 4045 / 4046 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Wood zodiac:Snake
Sexagenary cycle position 42 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 828 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 277 / 278 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 207 / 206 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 3
Digit sum: 15
Digit product: 80
Digital root: 6
Palindrome: No
Bit width: 9 bits
Reversed: 582
Recamán's sequence: a(169) = 285
Square (n²): 81,225
Cube (n³): 23,149,125
Divisor count: 8
σ(n) — sum of divisors: 480
φ(n) — Euler's totient: 144
Sum of prime factors: 27

Primality

Prime factorization: 3 × 5 × 19

Nearest primes: 283 (−2) · 293 (+8)

Divisors & multiples

All divisors (8)

1 · 3 · 5 · 15 · 19 · 57 · 95 · 285

Aliquot sum (sum of proper divisors): 195

Factor pairs (a × b = 285)

1 × 285

3 × 95

5 × 57

15 × 19

First multiples

285 · 570 (double) · 855 · 1,140 · 1,425 · 1,710 · 1,995 · 2,280 · 2,565 · 2,850

Sums & aliquot sequence

As consecutive integers: 142 + 143 94 + 95 + 96 55 + 56 + 57 + 58 + 59 45 + 46 + 47 + 48 + 49 + 50

Aliquot sequence: 285 → 195 → 141 → 51 → 21 → 11 → 1 → 0 — terminates at zero

Representations

In words: two hundred eighty-five
Ordinal: 285th
Roman numeral: CCLXXXV
Binary: 100011101
Octal: 435
Hexadecimal: 0x11D
Base64: AR0=
One's complement: 65,250 (16-bit)

In other bases

ternary (3) 101120

quaternary (4) 10131

quinary (5) 2120

senary (6) 1153

septenary (7) 555

nonary (9) 346

undecimal (11) 23a

duodecimal (12) 1b9

tridecimal (13) 18c

tetradecimal (14) 165

pentadecimal (15) 140

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): σπεʹ
Mayan (base 20): 𝋮·𝋥
Chinese: 二百八十五
Chinese (financial): 貳佰捌拾伍

In other modern scripts

Eastern Arabic ٢٨٥ Devanagari २८५ Bengali ২৮৫ Tamil ௨௮௫ Thai ๒๘๕ Tibetan ༢༨༥ Khmer ២៨៥ Lao ໒໘໕ Burmese ၂၈၅

Digit at this position in famous constants

π — Pi (π): Digit 285 = 9
e — Euler's number (e): Digit 285 = 0
φ — Golden ratio (φ): Digit 285 = 5
√2 — Pythagoras's (√2): Digit 285 = 0
ln 2 — Natural log of 2: Digit 285 = 3
γ — Euler-Mascheroni (γ): Digit 285 = 9

Also seen as

Unicode codepoint

ĝ

Latin Small Letter G With Circumflex

U+011D

Lowercase letter (Ll)

UTF-8 encoding: C4 9D (2 bytes).

Lookup U+011D on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00011D

RGB(0, 1, 29)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.29.

Address: 0.0.1.29
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.1.29

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