Number

1,840

1,840 is a composite number, even, a calendar year.

1,840 (one thousand eight hundred forty) is an even 4-digit number. It is a composite number with 20 divisors, and factors as 2⁴ × 5 × 23. Its proper divisors sum to 2,624, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is MDCCCXL and in binary, 11100110000.

Abundant Number Gapful Number Odious Number Pernicious Number Practical Number Recamán's Sequence Refactorable Number Self Number Semiperfect Number Year

Interestingness

★ ★ ★ ★ ☆

6 notable facts · grade B

1,828 1,829 1,830 1,831 1,832 1,833 1,834 1,835 1,836 1,837 1,838 1,839 1,840 1,841 1,842 1,843 1,844 1,845 1,846 1,847 1,848 1,849 1,850 1,851 1,852

less more

Notable events — 1840 AD

Feb 10 Queen Victoria marries Prince Albert.
Feb 6 The Treaty of Waitangi establishes British sovereignty in New Zealand.
May 6 Britain issues the Penny Black, the world's first adhesive postage stamp.
Nov 7 The Convention of Alexandria settles the Egypt-Ottoman crisis.
Dec 2 William Henry Harrison defeats Martin Van Buren in the US presidential election.

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: Wednesday
January 1, 1840
Ended on: Thursday
December 31, 1840
Friday the 13ths: 2
2 Friday the 13ths this year.
Easter Sunday: April 19
Sunday, April 19, 1840
Decade: 1840s
1840–1849
Century: 19th century
1801–1900
Millennium: 2nd millennium
1001–2000
Years ago: 186
186 years before 2026.
US presidential election: Yes
US holds a presidential election in years divisible by 4 starting from 1788.

In other calendars

Hebrew: 5600 / 5601 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 1255 / 1256 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Metal zodiac:Rat
Sexagenary cycle position 37 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 2383 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 1218 / 1219 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 1832 / 1833 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 1762 / 1761 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 4
Digit sum: 13
Digit product: 0
Digital root: 4
Palindrome: No
Bit width: 11 bits
Reversed: 481
Recamán's sequence: a(8,064) = 1,840
Square (n²): 3,385,600
Cube (n³): 6,229,504,000
Divisor count: 20
σ(n) — sum of divisors: 4,464
φ(n) — Euler's totient: 704
Sum of prime factors: 36

Primality

Prime factorization: 2 ⁴ × 5 × 23

Nearest primes: 1,831 (−9) · 1,847 (+7)

Divisors & multiples

All divisors (20)

1 · 2 · 4 · 5 · 8 · 10 · 16 · 20 · 23 · 40 · 46 · 80 · 92 · 115 · 184 · 230 · 368 · 460 · 920 (half) · 1840

Aliquot sum (sum of proper divisors): 2,624

Factor pairs (a × b = 1,840)

1 × 1840

2 × 920

4 × 460

5 × 368

8 × 230

10 × 184

16 × 115

20 × 92

23 × 80

40 × 46

First multiples

1,840 · 3,680 (double) · 5,520 · 7,360 · 9,200 · 11,040 · 12,880 · 14,720 · 16,560 · 18,400

Sums & aliquot sequence

As consecutive integers: 366 + 367 + 368 + 369 + 370 69 + 70 + … + 91 42 + 43 + … + 73

Aliquot sequence: 1,840 → 2,624 → 2,710 → 2,186 → 1,096 → 974 → 490 → 536 → 484 → 447 → 153 → 81 → 40 → 50 → 43 → 1 → 0 — terminates at zero

Continued fraction of √n

√1,840 = [42; (1, 8, 1, 1, 5, 5, 5, 1, 1, 8, 1, 84)]

Period length 12 — the block in parentheses repeats forever.

Representations

In words: one thousand eight hundred forty
Ordinal: 1840th
Roman numeral: MDCCCXL
Binary: 11100110000
Octal: 3460
Hexadecimal: 0x730
Base64: BzA=
One's complement: 63,695 (16-bit)
Scientific notation: 1.84 × 10³
As a duration: 1,840 s = 30 minutes, 40 seconds

In other bases

ternary (3) 2112011

quaternary (4) 130300

quinary (5) 24330

senary (6) 12304

septenary (7) 5236

nonary (9) 2464

undecimal (11) 1423

duodecimal (12) 1094

tridecimal (13) ab7

tetradecimal (14) 956

pentadecimal (15) 82a

As an angle

1,840° = 5 × 360° + 40°

40° ≈ 0.698 rad

Compass bearing: NE (northeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋 𒌋𒌋𒌋𒌋
Egyptian hieroglyphic: 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆
Greek (Milesian): ͵αωμʹ
Mayan (base 20): 𝋤·𝋬·𝋠
Chinese: 一千八百四十
Chinese (financial): 壹仟捌佰肆拾

In other modern scripts

Eastern Arabic ١٨٤٠ Devanagari १८४० Bengali ১৮৪০ Tamil ௧௮௪௦ Thai ๑๘๔๐ Tibetan ༡༨༤༠ Khmer ១៨៤០ Lao ໑໘໔໐ Burmese ၁၈၄၀

Digit at this position in famous constants

π — Pi (π): Digit 1,840 = 4
e — Euler's number (e): Digit 1,840 = 8
φ — Golden ratio (φ): Digit 1,840 = 1
√2 — Pythagoras's (√2): Digit 1,840 = 3
ln 2 — Natural log of 2: Digit 1,840 = 3
γ — Euler-Mascheroni (γ): Digit 1,840 = 0

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1840, here are decompositions:

17 + 1823 = 1840
29 + 1811 = 1840
53 + 1787 = 1840
107 + 1733 = 1840
131 + 1709 = 1840
173 + 1667 = 1840
227 + 1613 = 1840
233 + 1607 = 1840

Showing the first eight; more decompositions exist.

Unicode codepoint

Syriac Pthaha Above

U+0730

Non-spacing mark (Mn)

UTF-8 encoding: DC B0 (2 bytes).

Lookup U+0730 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000730

RGB(0, 7, 48)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.48.

Address: 0.0.7.48
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.7.48

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

Musical pitch

Heard as a frequency, 1,840 Hz is closest to:

Concert pitch (A4 = 440 Hz): A♯6 (1864.7 Hz, -23¢)
Scientific pitch (C4 = 256 Hz): A♯6 (1824.6 Hz, +15¢)
Baroque pitch (A4 = 415 Hz): B6 (1863.3 Hz, -22¢)

Position in π

The digit sequence 1840 first appears in π at position 7,639 of the decimal expansion (the 7,639ordinal-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 1840 on Pi Search ↗