239
239 is a prime, odd, a calendar year.
239 (two hundred thirty-nine) 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 CCXXXIX and in binary, 11101111.
Interestingness
Historical context — 239 AD
Calendar year
Year 239 (CCXXXIX) was a common year starting on Tuesday of the Julian calendar.
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Historical context — 239 BC
Calendar year
Year 239 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
-
Tuesday
January 1, 239
- Ended on
-
Tuesday
December 31, 239
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Decade
-
230s
230–239
- Century
-
3rd century
201–300
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,787
1787 years before 2026.
In other calendars
- Hebrew
-
3999 / 4000 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Earth zodiac:Goat
Sexagenary cycle position 56 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
782 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
231 / 232 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
161 / 160 Saka
Indian national calendar; year starts in March.
Properties
Primality
239 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√239 = [15; (2, 5, 1, 2, 4, 15, 4, 2, 1, 5, 2, 30)]
Period length 12 — the block in parentheses repeats forever.
Representations
- In words
- two hundred thirty-nine
- Ordinal
- 239th
- Roman numeral
- CCXXXIX
- Binary
- 11101111
- Octal
- 357
- Hexadecimal
- 0xEF
- Base64
- 7w==
- One's complement
- 16 (8-bit)
- Scientific notation
- 2.39 × 10²
- As a duration
- 239 s = 3 minutes, 59 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- σλθʹ
- Mayan (base 20)
- 𝋫·𝋳
- Chinese
- 二百三十九
- Chinese (financial)
- 貳佰參拾玖
Digit at this position in famous constants
- π — Pi (π)
- Digit 239 = 1
- e — Euler's number (e)
- Digit 239 = 2
- φ — Golden ratio (φ)
- Digit 239 = 2
- √2 — Pythagoras's (√2)
- Digit 239 = 4
- ln 2 — Natural log of 2
- Digit 239 = 1
- γ — Euler-Mascheroni (γ)
- Digit 239 = 6
Also seen as
UTF-8 encoding: C3 AF (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.239.
- Address
- 0.0.0.239
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.0.239
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The number 239 is an active NANP area code (North American Numbering Plan).
- Primary area
- Fort Myers / Naples
- Region
- Florida
- 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, 239 Hz is closest to:
- Concert pitch (A4 = 440 Hz): A♯3 (233.1 Hz, +43¢)
- Scientific pitch (C4 = 256 Hz): B3 (241.6 Hz, -19¢)
- Baroque pitch (A4 = 415 Hz): B3 (232.9 Hz, +45¢ — about midway to C4)
Related reading
- Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.