Number

380

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

380 (three hundred eighty) is an even 3-digit number. It is a composite number with 12 divisors, and factors as 2² × 5 × 19. Its proper divisors sum to 460, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is CCCLXXX and in binary, 101111100.

Abundant Number Arithmetic Number Cube-Free Evil Number Practical Number Pronic / Oblong Recamán's Sequence Semiperfect Number Year

Interestingness

★ ★ ★ ★ ☆

6 notable facts · grade B

368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392

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Historical context — 380 AD

Calendar year

Year 380 (CCCLXXX) was a leap 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 — 380 BC

Calendar year

Year 380 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: Leap year
Divisible by 4 and not by 100; February has 29 days.
Days in year: 366
ISO weeks: 52
Started on: Tuesday
January 1, 380
Ended on: Wednesday
December 31, 380
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 380s
380–389
Century: 4th century
301–400
Millennium: 1st millennium
1–1000
Years ago: 1,646
1646 years before 2026.

In other calendars

Hebrew: 4140 / 4141 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Metal zodiac:Dragon
Sexagenary cycle position 17 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 923 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 372 / 373 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 302 / 301 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 11
Digit product: 0
Digital root: 2
Palindrome: No
Bit width: 9 bits
Reversed: 83
Recamán's sequence: a(2,492) = 380
Square (n²): 144,400
Cube (n³): 54,872,000
Divisor count: 12
σ(n) — sum of divisors: 840
φ(n) — Euler's totient: 144
Sum of prime factors: 28

Primality

Prime factorization: 2 ² × 5 × 19

Nearest primes: 379 (−1) · 383 (+3)

Divisors & multiples

All divisors (12)

1 · 2 · 4 · 5 · 10 · 19 · 20 · 38 · 76 · 95 · 190 (half) · 380

Aliquot sum (sum of proper divisors): 460

Factor pairs (a × b = 380)

1 × 380

2 × 190

4 × 95

5 × 76

10 × 38

19 × 20

First multiples

380 · 760 (double) · 1,140 · 1,520 · 1,900 · 2,280 · 2,660 · 3,040 · 3,420 · 3,800

Sums & aliquot sequence

As consecutive integers: 74 + 75 + 76 + 77 + 78 44 + 45 + … + 51 11 + 12 + … + 29

Aliquot sequence: 380 → 460 → 548 → 418 → 302 → 154 → 134 → 70 → 74 → 40 → 50 → 43 → 1 → 0 — terminates at zero

Continued fraction of √n

√380 = [19; (2, 38)]

Period length 2 — the block in parentheses repeats forever.

Representations

In words: three hundred eighty
Ordinal: 380th
Roman numeral: CCCLXXX
Binary: 101111100
Octal: 574
Hexadecimal: 0x17C
Base64: AXw=
One's complement: 65,155 (16-bit)
Scientific notation: 3.8 × 10²
As a duration: 380 s = 6 minutes, 20 seconds

In other bases

ternary (3) 112002

quaternary (4) 11330

quinary (5) 3010

senary (6) 1432

septenary (7) 1052

nonary (9) 462

undecimal (11) 316

duodecimal (12) 278

tridecimal (13) 233

tetradecimal (14) 1d2

pentadecimal (15) 1a5

As an angle

380° = 1 × 360° + 20°

20° ≈ 0.349 rad

Compass bearing: NNE (north-northeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋
Egyptian hieroglyphic: 𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆
Greek (Milesian): τπʹ
Mayan (base 20): 𝋳·𝋠
Chinese: 三百八十
Chinese (financial): 參佰捌拾

In other modern scripts

Eastern Arabic ٣٨٠ Devanagari ३८० Bengali ৩৮০ Tamil ௩௮௦ Thai ๓๘๐ Tibetan ༣༨༠ Khmer ៣៨០ Lao ໓໘໐ Burmese ၃၈၀

Digit at this position in famous constants

π — Pi (π): Digit 380 = 5
e — Euler's number (e): Digit 380 = 0
φ — Golden ratio (φ): Digit 380 = 7
√2 — Pythagoras's (√2): Digit 380 = 0
ln 2 — Natural log of 2: Digit 380 = 4
γ — Euler-Mascheroni (γ): Digit 380 = 9

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 380, here are decompositions:

7 + 373 = 380
13 + 367 = 380
31 + 349 = 380
43 + 337 = 380
67 + 313 = 380
73 + 307 = 380
97 + 283 = 380
103 + 277 = 380

Showing the first eight; more decompositions exist.

Unicode codepoint

Latin Small Letter Z With Dot Above

U+017C

Lowercase letter (Ll)

UTF-8 encoding: C5 BC (2 bytes).

Lookup U+017C on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00017C

RGB(0, 1, 124)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.124.

Address: 0.0.1.124
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.1.124

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

NANP area code 380

The number 380 is an active NANP area code (North American Numbering Plan).

Primary area: Columbus
Region: Ohio
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.

Look up area code 380 ↗

Musical pitch

Heard as a frequency, 380 Hz is closest to:

Concert pitch (A4 = 440 Hz): F♯4 (370 Hz, +46¢ — about midway to G4)
Scientific pitch (C4 = 256 Hz): G4 (383.6 Hz, -16¢)
Baroque pitch (A4 = 415 Hz): G4 (369.7 Hz, +47¢ — about midway to G♯4)