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Number

85

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

Arithmetic Number Decagonal Deficient Number Evil Number Recamán's Sequence Semiprime Smith Number Squarefree Year

Historical context — 85 AD

Calendar year

AD 85 (LXXXV) was a common year starting on Saturday of the Julian calendar.

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

Historical context — 85 BC

Calendar year

Year 85 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: 52
Started on: Monday
January 1, 85
Ended on: Monday
December 31, 85
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 80s
80–89
Century: 1st century
1–100
Millennium: 1st millennium
1–1000
Years ago: 1,941
1941 years before 2026.

In other calendars

Hebrew: 3845 / 3846 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Wood zodiac:Rooster
Sexagenary cycle position 22 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 628 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 77 / 78 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 7 / 6 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 2
Digit sum: 13
Digit product: 40
Digital root: 4
Palindrome: No
Bit width: 7 bits
Reversed: 58
Recamán's sequence: a(53) = 85
Square (n²): 7,225
Cube (n³): 614,125
Divisor count: 4
σ(n) — sum of divisors: 108
φ(n) — Euler's totient: 64
Sum of prime factors: 22

Primality

Prime factorization: 5 × 17

Nearest primes: 83 (−2) · 89 (+4)

Divisors & multiples

All divisors (4)

1 · 5 · 17 · 85

Aliquot sum (sum of proper divisors): 23

Factor pairs (a × b = 85)

1 × 85

5 × 17

First multiples

85 · 170 (double) · 255 · 340 · 425 · 510 · 595 · 680 · 765 · 850

Sums & aliquot sequence

As a sum of two squares: 2² + 9² = 6² + 7²

As consecutive integers: 42 + 43 15 + 16 + 17 + 18 + 19 4 + 5 + … + 13

Aliquot sequence: 85 → 23 → 1 → 0 — terminates at zero

Representations

In words: eighty-five
Ordinal: 85th
Roman numeral: LXXXV
Binary: 1010101
Octal: 125
Hexadecimal: 0x55
Base64: VQ==
One's complement: 170 (8-bit)

In other bases

ternary (3) 10011

quaternary (4) 1111

quinary (5) 320

senary (6) 221

septenary (7) 151

nonary (9) 104

undecimal (11) 78

duodecimal (12) 71

tridecimal (13) 67

tetradecimal (14) 61

pentadecimal (15) 5a

Historical numeral systems

Babylonian (base 60): 𒁹 𒌋𒌋𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): πεʹ
Mayan (base 20): 𝋤·𝋥
Chinese: 八十五
Chinese (financial): 捌拾伍

In other modern scripts

Eastern Arabic ٨٥ Devanagari ८५ Bengali ৮৫ Tamil ௮௫ Thai ๘๕ Tibetan ༨༥ Khmer ៨៥ Lao ໘໕ Burmese ၈၅

Digit at this position in famous constants

π — Pi (π): Digit 85 = 8
e — Euler's number (e): Digit 85 = 1
φ — Golden ratio (φ): Digit 85 = 7
√2 — Pythagoras's (√2): Digit 85 = 0
ln 2 — Natural log of 2: Digit 85 = 5
γ — Euler-Mascheroni (γ): Digit 85 = 6

Also seen as

ASCII character

As an ASCII codepoint, 85 is U. Printable ASCII character U.

Hex color

#000055

RGB(0, 0, 85)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.85.

Address: 0.0.0.85
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.85

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

US numbered highway

Matches numbered highway designation:

I-85 — Montgomery, AL to Petersburg, VA.

Interstate 85 on Wikipedia ↗