311
311 is a prime, odd, a calendar year.
311 (three hundred eleven) 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 CCCXI and in binary, 100110111.
Interestingness
Historical context — 311 AD
Calendar year
Year 311 (CCCXI) was a common year starting on Monday of the Julian calendar.
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Historical context — 311 BC
Calendar year
Year 311 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
-
Sunday
January 1, 311
- Ended on
-
Sunday
December 31, 311
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Decade
-
310s
310–319
- Century
-
4th century
301–400
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,715
1715 years before 2026.
In other calendars
- Hebrew
-
4071 / 4072 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Metal zodiac:Goat
Sexagenary cycle position 8 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
854 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
303 / 304 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
233 / 232 Saka
Indian national calendar; year starts in March.
Properties
Primality
311 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√311 = [17; (1, 1, 1, 2, 1, 6, 3, 17, 3, 6, 1, 2, 1, 1, 1, 34)]
Period length 16 — the block in parentheses repeats forever.
Representations
- In words
- three hundred eleven
- Ordinal
- 311th
- Roman numeral
- CCCXI
- Binary
- 100110111
- Octal
- 467
- Hexadecimal
- 0x137
- Base64
- ATc=
- One's complement
- 65,224 (16-bit)
- Scientific notation
- 3.11 × 10²
- As a duration
- 311 s = 5 minutes, 11 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒁹
- Egyptian hieroglyphic
- 𓍢𓍢𓍢𓎆𓏺
- Greek (Milesian)
- τιαʹ
- Mayan (base 20)
- 𝋯·𝋫
- Chinese
- 三百一十一
- Chinese (financial)
- 參佰壹拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 311 = 6
- e — Euler's number (e)
- Digit 311 = 8
- φ — Golden ratio (φ)
- Digit 311 = 0
- √2 — Pythagoras's (√2)
- Digit 311 = 5
- ln 2 — Natural log of 2
- Digit 311 = 8
- γ — Euler-Mascheroni (γ)
- Digit 311 = 2
Also seen as
UTF-8 encoding: C4 B7 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.55.
- Address
- 0.0.1.55
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.1.55
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 311 Hz is closest to:
- Concert pitch (A4 = 440 Hz): D♯4 (311.1 Hz, -1¢)
- Scientific pitch (C4 = 256 Hz): D♯4 (304.4 Hz, +37¢)
- Baroque pitch (A4 = 415 Hz): E4 (310.9 Hz, +1¢)
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.