Number

399

399 is a composite number, odd, a calendar year.

Arithmetic Number Deficient Number Evil Number Harshad / Niven Recamán's Sequence Sphenic Number Squarefree Year

Historical context — 399 AD

Calendar year

Year 399 (CCCXCIX) was a common year starting on Saturday of the Julian calendar.

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

Notable events — 399 BC

Undated The Athenian philosopher Socrates is condemned to death and drinks hemlock.

Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0

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: Friday
January 1, 399
Ended on: Friday
December 31, 399
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 390s
390–399
Century: 4th century
301–400
Millennium: 1st millennium
1–1000
Years ago: 1,627
1627 years before 2026.

In other calendars

Hebrew: 4159 / 4160 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Earth zodiac:Pig
Sexagenary cycle position 36 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 942 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 391 / 392 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 321 / 320 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 3
Digit sum: 21
Digit product: 243
Digital root: 3
Palindrome: No
Bit width: 9 bits
Reversed: 993
Recamán's sequence: a(2,454) = 399
Square (n²): 159,201
Cube (n³): 63,521,199
Divisor count: 8
σ(n) — sum of divisors: 640
φ(n) — Euler's totient: 216
Sum of prime factors: 29

Primality

Prime factorization: 3 × 7 × 19

Nearest primes: 397 (−2) · 401 (+2)

Divisors & multiples

All divisors (8)

1 · 3 · 7 · 19 · 21 · 57 · 133 · 399

Aliquot sum (sum of proper divisors): 241

Factor pairs (a × b = 399)

1 × 399

3 × 133

7 × 57

19 × 21

First multiples

399 · 798 (double) · 1,197 · 1,596 · 1,995 · 2,394 · 2,793 · 3,192 · 3,591 · 3,990

Sums & aliquot sequence

As consecutive integers: 199 + 200 132 + 133 + 134 64 + 65 + 66 + 67 + 68 + 69 54 + 55 + … + 60

Aliquot sequence: 399 → 241 → 1 → 0 — terminates at zero

Representations

In words: three hundred ninety-nine
Ordinal: 399th
Roman numeral: CCCXCIX
Binary: 110001111
Octal: 617
Hexadecimal: 0x18F
Base64: AY8=
One's complement: 65,136 (16-bit)

In other bases

ternary (3) 112210

quaternary (4) 12033

quinary (5) 3044

senary (6) 1503

septenary (7) 1110

nonary (9) 483

undecimal (11) 333

duodecimal (12) 293

tridecimal (13) 249

tetradecimal (14) 207

pentadecimal (15) 1b9

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): τϟθʹ
Mayan (base 20): 𝋳·𝋳
Chinese: 三百九十九
Chinese (financial): 參佰玖拾玖

In other modern scripts

Eastern Arabic ٣٩٩ Devanagari ३९९ Bengali ৩৯৯ Tamil ௩௯௯ Thai ๓๙๙ Tibetan ༣༩༩ Khmer ៣៩៩ Lao ໓໙໙ Burmese ၃၉၉

Digit at this position in famous constants

π — Pi (π): Digit 399 = 0
e — Euler's number (e): Digit 399 = 4
φ — Golden ratio (φ): Digit 399 = 7
√2 — Pythagoras's (√2): Digit 399 = 4
ln 2 — Natural log of 2: Digit 399 = 9
γ — Euler-Mascheroni (γ): Digit 399 = 3

Also seen as

Unicode codepoint

Latin Capital Letter Schwa

U+018F

Uppercase letter (Lu)

UTF-8 encoding: C6 8F (2 bytes).

Lookup U+018F on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00018F

RGB(0, 1, 143)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.143.

Address: 0.0.1.143
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.1.143

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