Number

1,920

1,920 is a composite number, even, a calendar year.

1,920 (one thousand nine hundred twenty) is an even 4-digit number. It is a composite number with 32 divisors, and factors as 2⁷ × 3 × 5. Its proper divisors sum to 4,200, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is MCMXX and in binary, 11110000000.

Abundant Number Evil Number Gapful Number Happy Number Harshad / Niven Highly Abundant Practical Number Recamán's Sequence Refactorable Number Semiperfect Number Year

Interestingness

★ ★ ★ ★ ★

8 notable facts · grade A

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 1,932

less more

Notable events — 1920 AD

Jan 16 Prohibition takes effect in the United States.
Jan 16 The League of Nations holds its first council meeting in Paris.
Aug 18 The 19th Amendment is ratified, giving American women the right to vote.
Nov 2 KDKA in Pittsburgh begins the first commercial radio broadcasts.
Nov 2 Warren G. Harding wins the US presidential election in a landslide.

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

Year facts

Year type: Leap year
Divisible by 4 and not by 100; February has 29 days.
Days in year: 366
ISO weeks: 53
Long year: contains 53 ISO weeks.
Started on: Thursday
January 1, 1920
Ended on: Friday
December 31, 1920
Friday the 13ths: 2
2 Friday the 13ths this year.
Easter Sunday: April 4
Sunday, April 4, 1920
Decade: 1920s
1920–1929
Century: 20th century
1901–2000
Millennium: 2nd millennium
1001–2000
Years ago: 106
106 years before 2026.
US presidential election: Yes
US holds a presidential election in years divisible by 4 starting from 1788.
Summer Olympics: Yes

In other calendars

Hebrew: 5680 / 5681 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 1338 / 1339 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Metal zodiac:Monkey
Sexagenary cycle position 57 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 2463 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 1298 / 1299 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 1912 / 1913 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 1842 / 1841 Saka
Indian national calendar; year starts in March.
Japanese: Taishō 9
Reign-era counting from the start of each emperor's reign.

Properties

Parity: Even
Digit count: 4
Digit sum: 12
Digit product: 0
Digital root: 3
Palindrome: No
Bit width: 11 bits
Reversed: 291
Recamán's sequence: a(7,904) = 1,920
Square (n²): 3,686,400
Cube (n³): 7,077,888,000
Divisor count: 32
σ(n) — sum of divisors: 6,120
φ(n) — Euler's totient: 512
Sum of prime factors: 22

Primality

Prime factorization: 2 ⁷ × 3 × 5

Nearest primes: 1,913 (−7) · 1,931 (+11)

Divisors & multiples

All divisors (32)

1 · 2 · 3 · 4 · 5 · 6 · 8 · 10 · 12 · 15 · 16 · 20 · 24 · 30 · 32 · 40 · 48 · 60 · 64 · 80 · 96 · 120 · 128 · 160 · 192 · 240 · 320 · 384 · 480 · 640 · 960 (half) · 1920

Aliquot sum (sum of proper divisors): 4,200

Factor pairs (a × b = 1,920)

1 × 1920

2 × 960

3 × 640

4 × 480

5 × 384

6 × 320

8 × 240

10 × 192

12 × 160

15 × 128

16 × 120

20 × 96

24 × 80

30 × 64

32 × 60

40 × 48

First multiples

1,920 · 3,840 (double) · 5,760 · 7,680 · 9,600 · 11,520 · 13,440 · 15,360 · 17,280 · 19,200

Sums & aliquot sequence

As consecutive integers: 639 + 640 + 641 382 + 383 + 384 + 385 + 386 121 + 122 + … + 135

Aliquot sequence: 1,920 → 4,200 → 10,680 → 21,720 → 43,800 → 93,840 → 227,568 → 415,248 → 688,848 → 1,120,560 → 3,164,880 → 6,646,992 → 12,086,928 → 28,342,032 → 45,117,552 → 79,735,568 → 89,795,248 — unresolved within range

Continued fraction of √n

√1,920 = [43; (1, 4, 2, 21, 2, 4, 1, 86)]

Period length 8 — the block in parentheses repeats forever.

Representations

In words: one thousand nine hundred twenty
Ordinal: 1920th
Roman numeral: MCMXX
Binary: 11110000000
Octal: 3600
Hexadecimal: 0x780
Base64: B4A=
One's complement: 63,615 (16-bit)
Scientific notation: 1.92 × 10³
As a duration: 1,920 s = 32 minutes

In other bases

ternary (3) 2122010

quaternary (4) 132000

quinary (5) 30140

senary (6) 12520

septenary (7) 5412

nonary (9) 2563

undecimal (11) 1496

duodecimal (12) 1140

tridecimal (13) b49

tetradecimal (14) 9b2

pentadecimal (15) 880

As an angle

1,920° = 5 × 360° + 120°

120° ≈ 2.094 rad

Compass bearing: ESE (east-southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒁹𒁹 ·
Egyptian hieroglyphic: 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆
Greek (Milesian): ͵αϡκʹ
Mayan (base 20): 𝋤·𝋰·𝋠
Chinese: 一千九百二十
Chinese (financial): 壹仟玖佰貳拾

In other modern scripts

Eastern Arabic ١٩٢٠ Devanagari १९२० Bengali ১৯২০ Tamil ௧௯௨௦ Thai ๑๙๒๐ Tibetan ༡༩༢༠ Khmer ១៩២០ Lao ໑໙໒໐ Burmese ၁၉၂၀

Digit at this position in famous constants

π — Pi (π): Digit 1,920 = 4
e — Euler's number (e): Digit 1,920 = 7
φ — Golden ratio (φ): Digit 1,920 = 2
√2 — Pythagoras's (√2): Digit 1,920 = 3
ln 2 — Natural log of 2: Digit 1,920 = 1
γ — Euler-Mascheroni (γ): Digit 1,920 = 5

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1920, here are decompositions:

7 + 1913 = 1920
13 + 1907 = 1920
19 + 1901 = 1920
31 + 1889 = 1920
41 + 1879 = 1920
43 + 1877 = 1920
47 + 1873 = 1920
53 + 1867 = 1920

Showing the first eight; more decompositions exist.

Unicode codepoint

Thaana Letter Haa

U+0780

Other letter (Lo)

UTF-8 encoding: DE 80 (2 bytes).

Lookup U+0780 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000780

RGB(0, 7, 128)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.128.

Address: 0.0.7.128
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.7.128

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

Musical pitch

Heard as a frequency, 1,920 Hz is closest to:

Concert pitch (A4 = 440 Hz): B6 (1975.5 Hz, -49¢ — about midway to A♯6)
Scientific pitch (C4 = 256 Hz): B6 (1933.1 Hz, -12¢)
Baroque pitch (A4 = 415 Hz): C7 (1974.1 Hz, -48¢ — about midway to B6)

Position in π

The digit sequence 1920 first appears in π at position 6,751 of the decimal expansion (the 6,751ordinal-suffix:st 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 1920 on Pi Search ↗