Number

1,919

1,919 is a composite number, odd, a calendar year.

1,919 (one thousand nine hundred nineteen) is an odd 4-digit number. It is a composite number with 4 divisors, and factors as 19 × 101. Written other ways, in Roman numerals it is MCMXIX and in binary, 11101111111.

Arithmetic Number Cube-Free Deficient Number Evil Number Flippable Gapful Number Recamán's Sequence Self Number Semiprime Squarefree Undulating Number Year

Interestingness

★ ★ ★ ★ ★

9 notable facts · grade A

1,907 1,908 1,909 1,910 1,911 1,912 1,913 1,914 1,915 1,916 1,917 1,918 1,919 1,920 1,921 1,922 1,923 1,924 1,925 1,926 1,927 1,928 1,929 1,930 1,931

less more

Notable events — 1919 AD

Jan 16 The 18th Amendment, establishing Prohibition, is ratified.
Apr 13 British troops fire on a crowd at Amritsar, killing hundreds.
Jun 28 The Treaty of Versailles is signed at the Paris Peace Conference.
Jul 19 Walter Gropius founds the Bauhaus school in Weimar (school opened April 1).
Oct 28 The Volstead Act passes over Wilson's veto, enforcing Prohibition.

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: Wednesday
January 1, 1919
Ended on: Wednesday
December 31, 1919
Friday the 13ths: 1
One Friday the 13th this year.
Easter Sunday: April 20
Sunday, April 20, 1919
Decade: 1910s
1910–1919
Century: 20th century
1901–2000
Millennium: 2nd millennium
1001–2000
Years ago: 107
107 years before 2026.

In other calendars

Hebrew: 5679 / 5680 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 1337 / 1338 AH
Lunar calendar; year spans differ from Gregorian.
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: 2462 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 1297 / 1298 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 1911 / 1912 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 1841 / 1840 Saka
Indian national calendar; year starts in March.
Japanese: Taishō 8
Reign-era counting from the start of each emperor's reign.

Properties

Parity: Odd
Digit count: 4
Digit sum: 20
Digit product: 81
Digital root: 2
Palindrome: No
Bit width: 11 bits
Reversed: 9,191
Flips to (rotate 180°): 6,161
Recamán's sequence: a(7,906) = 1,919
Square (n²): 3,682,561
Cube (n³): 7,066,834,559
Divisor count: 4
σ(n) — sum of divisors: 2,040
φ(n) — Euler's totient: 1,800
Sum of prime factors: 120

Primality

Prime factorization: 19 × 101

Nearest primes: 1,913 (−6) · 1,931 (+12)

Divisors & multiples

All divisors (4)

1 · 19 · 101 · 1919

Aliquot sum (sum of proper divisors): 121

Factor pairs (a × b = 1,919)

1 × 1919

19 × 101

First multiples

1,919 · 3,838 (double) · 5,757 · 7,676 · 9,595 · 11,514 · 13,433 · 15,352 · 17,271 · 19,190

Sums & aliquot sequence

As consecutive integers: 959 + 960 92 + 93 + … + 110 32 + 33 + … + 69

Aliquot sequence: 1,919 → 121 → 12 → 16 → 15 → 9 → 4 → 3 → 1 → 0 — terminates at zero

Continued fraction of √n

√1,919 = [43; (1, 4, 6, 17, 2, 1, 3, 3, 4, 3, 3, 1, 2, 17, 6, 4, 1, 86)]

Period length 18 — the block in parentheses repeats forever.

Representations

In words: one thousand nine hundred nineteen
Ordinal: 1919th
Roman numeral: MCMXIX
Binary: 11101111111
Octal: 3577
Hexadecimal: 0x77F
Base64: B38=
One's complement: 63,616 (16-bit)
Scientific notation: 1.919 × 10³
As a duration: 1,919 s = 31 minutes, 59 seconds

In other bases

ternary (3) 2122002

quaternary (4) 131333

quinary (5) 30134

senary (6) 12515

septenary (7) 5411

nonary (9) 2562

undecimal (11) 1495

duodecimal (12) 113b

tridecimal (13) b48

tetradecimal (14) 9b1

pentadecimal (15) 87e

As an angle

1,919° = 5 × 360° + 119°

119° ≈ 2.077 rad

Compass bearing: ESE (east-southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): ͵αϡιθʹ
Mayan (base 20): 𝋤·𝋯·𝋳
Chinese: 一千九百一十九
Chinese (financial): 壹仟玖佰壹拾玖

In other modern scripts

Eastern Arabic ١٩١٩ Devanagari १९१९ Bengali ১৯১৯ Tamil ௧௯௧௯ Thai ๑๙๑๙ Tibetan ༡༩༡༩ Khmer ១៩១៩ Lao ໑໙໑໙ Burmese ၁၉၁၉

Digit at this position in famous constants

π — Pi (π): Digit 1,919 = 9
e — Euler's number (e): Digit 1,919 = 1
φ — Golden ratio (φ): Digit 1,919 = 1
√2 — Pythagoras's (√2): Digit 1,919 = 7
ln 2 — Natural log of 2: Digit 1,919 = 0
γ — Euler-Mascheroni (γ): Digit 1,919 = 7

Also seen as

Unicode codepoint

Arabic Letter Kaf With Two Dots Above

U+077F

Other letter (Lo)

UTF-8 encoding: DD BF (2 bytes).

Lookup U+077F on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00077F

RGB(0, 7, 127)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.127.

Address: 0.0.7.127
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.7.127

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

Musical pitch

Heard as a frequency, 1,919 Hz is closest to:

Concert pitch (A4 = 440 Hz): A♯6 (1864.7 Hz, +50¢ — about midway to B6)
Scientific pitch (C4 = 256 Hz): B6 (1933.1 Hz, -13¢)
Baroque pitch (A4 = 415 Hz): C7 (1974.1 Hz, -49¢ — about midway to B6)

Position in π

The digit sequence 1919 first appears in π at position 14,508 of the decimal expansion (the 14,508ordinal-suffix:th digit after the integer 3).

Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.

Look up 1919 on Pi Search ↗