Number

222

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

222 (two hundred twenty-two) is an even 3-digit number. It is a composite number with 8 divisors, and factors as 2 × 3 × 37. Its proper divisors sum to 234, more than the number itself, making it an abundant number. Its digits read the same forwards and backwards, so it is a palindromic number. Written other ways, in Roman numerals it is CCXXII and in binary, 11011110.

Abundant Number Arithmetic Number Cube-Free Evil Number Harshad / Niven Moran Number Palindrome Recamán's Sequence Repdigit Self Number Semiperfect Number Sphenic Number Squarefree Year

Interestingness

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11 notable facts · grade A

210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234

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Historical context — 222 AD

Calendar year

Year 222 (CCXXII) was a common year starting on Tuesday of the Julian calendar.

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

Historical context — 222 BC

Calendar year

Year 222 BC was a year of the pre-Julian Roman calendar.

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: Tuesday
January 1, 222
Ended on: Tuesday
December 31, 222
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 220s
220–229
Century: 3rd century
201–300
Millennium: 1st millennium
1–1000
Years ago: 1,804
1804 years before 2026.

In other calendars

Hebrew: 3982 / 3983 AM
Rosh Hashanah falls in September/October.
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: 765 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 214 / 215 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 144 / 143 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 6
Digit product: 8
Digital root: 6
Palindrome: Yes
Bit width: 8 bits
Recamán's sequence: a(2,588) = 222
Square (n²): 49,284
Cube (n³): 10,941,048
Divisor count: 8
σ(n) — sum of divisors: 456
φ(n) — Euler's totient: 72
Sum of prime factors: 42

Primality

Prime factorization: 2 × 3 × 37

Nearest primes: 211 (−11) · 223 (+1)

Divisors & multiples

All divisors (8)

1 · 2 · 3 · 6 · 37 · 74 · 111 (half) · 222

Aliquot sum (sum of proper divisors): 234

Factor pairs (a × b = 222)

1 × 222

2 × 111

3 × 74

6 × 37

First multiples

222 · 444 (double) · 666 · 888 · 1,110 · 1,332 · 1,554 · 1,776 · 1,998 · 2,220

Sums & aliquot sequence

As consecutive integers: 73 + 74 + 75 54 + 55 + 56 + 57 13 + 14 + … + 24

Aliquot sequence: 222 → 234 → 312 → 528 → 960 → 2,088 → 3,762 → 5,598 → 6,570 → 10,746 → 13,254 → 13,830 → 19,434 → 20,886 → 21,606 → 25,098 → 26,742 — unresolved within range

Continued fraction of √n

√222 = [14; (1, 8, 1, 28)]

Period length 4 — the block in parentheses repeats forever.

Representations

In words: two hundred twenty-two
Ordinal: 222nd
Roman numeral: CCXXII
Binary: 11011110
Octal: 336
Hexadecimal: 0xDE
Base64: 3g==
One's complement: 33 (8-bit)
Scientific notation: 2.22 × 10²
As a duration: 222 s = 3 minutes, 42 seconds

In other bases

ternary (3) 22020

quaternary (4) 3132

quinary (5) 1342

senary (6) 1010

septenary (7) 435

nonary (9) 266

undecimal (11) 192

duodecimal (12) 166

tridecimal (13) 141

tetradecimal (14) 11c

pentadecimal (15) ec

Palindromic in base 13

As an angle

222°

222° ≈ 3.875 rad

Compass bearing: SW (southwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓎆𓎆𓏺𓏺
Greek (Milesian): σκβʹ
Mayan (base 20): 𝋫·𝋢
Chinese: 二百二十二
Chinese (financial): 貳佰貳拾貳

In other modern scripts

Eastern Arabic ٢٢٢ Devanagari २२२ Bengali ২২২ Tamil ௨௨௨ Thai ๒๒๒ Tibetan ༢༢༢ Khmer ២២២ Lao ໒໒໒ Burmese ၂၂၂

Digit at this position in famous constants

π — Pi (π): Digit 222 = 2
e — Euler's number (e): Digit 222 = 8
φ — Golden ratio (φ): Digit 222 = 9
√2 — Pythagoras's (√2): Digit 222 = 3
ln 2 — Natural log of 2: Digit 222 = 7
γ — Euler-Mascheroni (γ): Digit 222 = 5

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 222, here are decompositions:

11 + 211 = 222
23 + 199 = 222
29 + 193 = 222
31 + 191 = 222
41 + 181 = 222
43 + 179 = 222
59 + 163 = 222
71 + 151 = 222

Showing the first eight; more decompositions exist.

Unicode codepoint

Latin Capital Letter Thorn

U+00DE

Uppercase letter (Lu)

UTF-8 encoding: C3 9E (2 bytes).

Lookup U+00DE on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#0000DE

RGB(0, 0, 222)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.222.

Address: 0.0.0.222
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.222

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

Musical pitch

Heard as a frequency, 222 Hz is closest to:

Concert pitch (A4 = 440 Hz): A3 (220 Hz, +16¢)
Scientific pitch (C4 = 256 Hz): A♯3 (228.1 Hz, -47¢ — about midway to A3)
Baroque pitch (A4 = 415 Hz): A♯3 (219.8 Hz, +17¢)