223
223 is a prime, odd, a calendar year.
223 (two hundred twenty-three) is an odd 3-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is CCXXIII and in binary, 11011111.
Interestingness
Historical context — 223 AD
Calendar year
Year 223 (CCXXIII) was a common year starting on Wednesday of the Julian calendar.
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Historical context — 223 BC
Calendar year
Year 223 BC was a year of the pre-Julian Roman calendar.
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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
-
Wednesday
January 1, 223
- Ended on
-
Wednesday
December 31, 223
- Friday the 13ths
-
1
One Friday the 13th this year.
- Decade
-
220s
220–229
- Century
-
3rd century
201–300
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,803
1803 years before 2026.
In other calendars
- Hebrew
-
3983 / 3984 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Water zodiac:Rabbit
Sexagenary cycle position 40 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
766 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
215 / 216 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
145 / 144 Saka
Indian national calendar; year starts in March.
Properties
Primality
223 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√223 = [14; (1, 13, 1, 28)]
Period length 4 — the block in parentheses repeats forever.
Representations
- In words
- two hundred twenty-three
- Ordinal
- 223rd
- Roman numeral
- CCXXIII
- Binary
- 11011111
- Octal
- 337
- Hexadecimal
- 0xDF
- Base64
- 3w==
- One's complement
- 32 (8-bit)
- Scientific notation
- 2.23 × 10²
- As a duration
- 223 s = 3 minutes, 43 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓎆𓎆𓏺𓏺𓏺
- Greek (Milesian)
- σκγʹ
- Mayan (base 20)
- 𝋫·𝋣
- Chinese
- 二百二十三
- Chinese (financial)
- 貳佰貳拾參
Digit at this position in famous constants
- π — Pi (π)
- Digit 223 = 8
- e — Euler's number (e)
- Digit 223 = 9
- φ — Golden ratio (φ)
- Digit 223 = 6
- √2 — Pythagoras's (√2)
- Digit 223 = 4
- ln 2 — Natural log of 2
- Digit 223 = 5
- γ — Euler-Mascheroni (γ)
- Digit 223 = 3
Also seen as
UTF-8 encoding: C3 9F (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.223.
- Address
- 0.0.0.223
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.223
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The number 223 is an active NANP area code (North American Numbering Plan).
- Primary area
- Lancaster / Harrisburg
- 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.
Heard as a frequency, 223 Hz is closest to:
- Concert pitch (A4 = 440 Hz): A3 (220 Hz, +23¢)
- Scientific pitch (C4 = 256 Hz): A♯3 (228.1 Hz, -39¢)
- Baroque pitch (A4 = 415 Hz): A♯3 (219.8 Hz, +25¢)
On an ingredients label, E223 is Sodium metabisulphite, a preservative.
Related reading
- Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.