Number

822

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

822 (eight hundred twenty-two) is an even 3-digit number. It is a composite number with 8 divisors, and factors as 2 × 3 × 137. Its proper divisors sum to 834, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is DCCCXXII and in binary, 1100110110.

Abundant Number Arithmetic Number Cube-Free Evil Number Recamán's Sequence Semiperfect Number Sphenic Number Squarefree Year

Interestingness

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6 notable facts · grade B

810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834

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Historical context — 822 AD

Calendar year

Year 822 (DCCCXXII) 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 — 822 BC

Decade

This article concerns the period 829 BC – 820 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, 822
Ended on: Saturday
December 31, 822
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 820s
820–829
Century: 9th century
801–900
Millennium: 1st millennium
1–1000
Years ago: 1,204
1204 years before 2026.

In other calendars

Hebrew: 4582 / 4583 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 206 / 207 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Water zodiac:Tiger
Sexagenary cycle position 39 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 1365 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 200 / 201 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 814 / 815 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 744 / 743 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 12
Digit product: 32
Digital root: 3
Palindrome: No
Bit width: 10 bits
Reversed: 228
Recamán's sequence: a(2,104) = 822
Square (n²): 675,684
Cube (n³): 555,412,248
Divisor count: 8
σ(n) — sum of divisors: 1,656
φ(n) — Euler's totient: 272
Sum of prime factors: 142

Primality

Prime factorization: 2 × 3 × 137

Nearest primes: 821 (−1) · 823 (+1)

Divisors & multiples

All divisors (8)

1 · 2 · 3 · 6 · 137 · 274 · 411 (half) · 822

Aliquot sum (sum of proper divisors): 834

Factor pairs (a × b = 822)

1 × 822

2 × 411

3 × 274

6 × 137

First multiples

822 · 1,644 (double) · 2,466 · 3,288 · 4,110 · 4,932 · 5,754 · 6,576 · 7,398 · 8,220

Sums & aliquot sequence

As consecutive integers: 273 + 274 + 275 204 + 205 + 206 + 207 63 + 64 + … + 74

Aliquot sequence: 822 → 834 → 846 → 1,026 → 1,374 → 1,386 → 2,358 → 2,790 → 4,698 → 6,192 → 11,540 → 12,736 → 12,664 → 11,096 → 11,104 → 10,820 → 11,944 — unresolved within range

Continued fraction of √n

√822 = [28; (1, 2, 28, 2, 1, 56)]

Period length 6 — the block in parentheses repeats forever.

Representations

In words: eight hundred twenty-two
Ordinal: 822nd
Roman numeral: DCCCXXII
Binary: 1100110110
Octal: 1466
Hexadecimal: 0x336
Base64: AzY=
One's complement: 64,713 (16-bit)
Scientific notation: 8.22 × 10²
As a duration: 822 s = 13 minutes, 42 seconds

In other bases

ternary (3) 1010110

quaternary (4) 30312

quinary (5) 11242

senary (6) 3450

septenary (7) 2253

nonary (9) 1113

undecimal (11) 688

duodecimal (12) 586

tridecimal (13) 4b3

tetradecimal (14) 42a

pentadecimal (15) 39c

As an angle

822° = 2 × 360° + 102°

102° ≈ 1.78 rad

Compass bearing: ESE (east-southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓏺𓏺
Greek (Milesian): ωκβʹ
Mayan (base 20): 𝋢·𝋡·𝋢
Chinese: 八百二十二
Chinese (financial): 捌佰貳拾貳

In other modern scripts

Eastern Arabic ٨٢٢ Devanagari ८२२ Bengali ৮২২ Tamil ௮௨௨ Thai ๘๒๒ Tibetan ༨༢༢ Khmer ៨២២ Lao ໘໒໒ Burmese ၈၂၂

Digit at this position in famous constants

π — Pi (π): Digit 822 = 4
e — Euler's number (e): Digit 822 = 7
φ — Golden ratio (φ): Digit 822 = 2
√2 — Pythagoras's (√2): Digit 822 = 0
ln 2 — Natural log of 2: Digit 822 = 9
γ — Euler-Mascheroni (γ): Digit 822 = 7

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 822, here are decompositions:

11 + 811 = 822
13 + 809 = 822
53 + 769 = 822
61 + 761 = 822
71 + 751 = 822
79 + 743 = 822
83 + 739 = 822
89 + 733 = 822

Showing the first eight; more decompositions exist.

Unicode codepoint

Combining Long Stroke Overlay

U+0336

Non-spacing mark (Mn)

UTF-8 encoding: CC B6 (2 bytes).

Lookup U+0336 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000336

RGB(0, 3, 54)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.54.

Address: 0.0.3.54
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.3.54

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

Musical pitch

Heard as a frequency, 822 Hz is closest to:

Concert pitch (A4 = 440 Hz): G♯5 (830.6 Hz, -18¢)
Scientific pitch (C4 = 256 Hz): G♯5 (812.7 Hz, +20¢)
Baroque pitch (A4 = 415 Hz): A5 (830 Hz, -17¢)