Number

878

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

878 (eight hundred seventy-eight) is an even 3-digit number. It is a composite number with 4 divisors, and factors as 2 × 439. Its digits read the same forwards and backwards, so it is a palindromic number. Written other ways, in Roman numerals it is DCCCLXXVIII and in binary, 1101101110.

Arithmetic Number Consecutive Digits Cube-Free Deficient Number Odious Number Palindrome Pernicious Number Recamán's Sequence Semiprime Squarefree Undulating Number Year

Interestingness

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8 notable facts · grade A

866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890

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Historical context — 878 AD

Calendar year

Year 878 (DCCCLXXVIII) was a common year starting on Wednesday of the Julian calendar.

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

Historical context — 878 BC

Decade

This article concerns the period 879 BC – 870 BC.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 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: Saturday
January 1, 878
Ended on: Saturday
December 31, 878
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 870s
870–879
Century: 9th century
801–900
Millennium: 1st millennium
1–1000
Years ago: 1,148
1148 years before 2026.

In other calendars

Hebrew: 4638 / 4639 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 264 / 265 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Earth zodiac:Dog
Sexagenary cycle position 35 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 1421 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 256 / 257 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 870 / 871 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 800 / 799 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 23
Digit product: 448
Digital root: 5
Palindrome: Yes
Bit width: 10 bits
Recamán's sequence: a(775) = 878
Square (n²): 770,884
Cube (n³): 676,836,152
Divisor count: 4
σ(n) — sum of divisors: 1,320
φ(n) — Euler's totient: 438
Sum of prime factors: 441

Primality

Prime factorization: 2 × 439

Nearest primes: 877 (−1) · 881 (+3)

Divisors & multiples

All divisors (4)

1 · 2 · 439 (half) · 878

Aliquot sum (sum of proper divisors): 442

Factor pairs (a × b = 878)

1 × 878

2 × 439

First multiples

878 · 1,756 (double) · 2,634 · 3,512 · 4,390 · 5,268 · 6,146 · 7,024 · 7,902 · 8,780

Sums & aliquot sequence

As consecutive integers: 218 + 219 + 220 + 221

Aliquot sequence: 878 → 442 → 314 → 160 → 218 → 112 → 136 → 134 → 70 → 74 → 40 → 50 → 43 → 1 → 0 — terminates at zero

Continued fraction of √n

√878 = [29; (1, 1, 1, 2, 2, 4, 1, 28, 1, 4, 2, 2, 1, 1, 1, 58)]

Period length 16 — the block in parentheses repeats forever.

Representations

In words: eight hundred seventy-eight
Ordinal: 878th
Roman numeral: DCCCLXXVIII
Binary: 1101101110
Octal: 1556
Hexadecimal: 0x36E
Base64: A24=
One's complement: 64,657 (16-bit)
Scientific notation: 8.78 × 10²
As a duration: 878 s = 14 minutes, 38 seconds

In other bases

ternary (3) 1012112

quaternary (4) 31232

quinary (5) 12003

senary (6) 4022

septenary (7) 2363

nonary (9) 1175

undecimal (11) 729

duodecimal (12) 612

tridecimal (13) 527

tetradecimal (14) 46a

pentadecimal (15) 3d8

As an angle

878° = 2 × 360° + 158°

158° ≈ 2.758 rad

Compass bearing: SSE (south-southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): ωοηʹ
Mayan (base 20): 𝋢·𝋣·𝋲
Chinese: 八百七十八
Chinese (financial): 捌佰柒拾捌

In other modern scripts

Eastern Arabic ٨٧٨ Devanagari ८७८ Bengali ৮৭৮ Tamil ௮௭௮ Thai ๘๗๘ Tibetan ༨༧༨ Khmer ៨៧៨ Lao ໘໗໘ Burmese ၈၇၈

Digit at this position in famous constants

π — Pi (π): Digit 878 = 2
e — Euler's number (e): Digit 878 = 2
φ — Golden ratio (φ): Digit 878 = 8
√2 — Pythagoras's (√2): Digit 878 = 9
ln 2 — Natural log of 2: Digit 878 = 3
γ — Euler-Mascheroni (γ): Digit 878 = 0

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 878, here are decompositions:

19 + 859 = 878
67 + 811 = 878
109 + 769 = 878
127 + 751 = 878
139 + 739 = 878
151 + 727 = 878
271 + 607 = 878
277 + 601 = 878

Showing the first eight; more decompositions exist.

Unicode codepoint

Combining Latin Small Letter V

U+036E

Non-spacing mark (Mn)

UTF-8 encoding: CD AE (2 bytes).

Lookup U+036E on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00036E

RGB(0, 3, 110)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.110.

Address: 0.0.3.110
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.3.110

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

NANP area code 878

The number 878 is an active NANP area code (North American Numbering Plan).

Primary area: Pittsburgh
Region: Pennsylvania
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 878 ↗

Musical pitch

Heard as a frequency, 878 Hz is closest to:

Concert pitch (A4 = 440 Hz): A5 (880 Hz, -4¢)
Scientific pitch (C4 = 256 Hz): A5 (861.1 Hz, +34¢)
Baroque pitch (A4 = 415 Hz): A♯5 (879.4 Hz, -3¢)