1,900
1,900 is a composite number, even, a calendar year.
1,900 (one thousand nine hundred) is an even 4-digit number. It is a composite number with 18 divisors, and factors as 2² × 5² × 19. Its proper divisors sum to 2,440, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is MCM and in binary, 11101101100.
Interestingness
Notable events — 1900 AD
- Jun 20 The Boxer Rebellion begins as Chinese militants besiege foreign legations in Beijing.
- Sep 8 The Galveston hurricane kills an estimated 8,000-12,000 in Texas.
- Nov 6 William McKinley is re-elected US president with Theodore Roosevelt as VP.
- Dec 14 Max Planck presents his quantum hypothesis, founding quantum theory.
- Jul 2 Count Zeppelin makes the first successful flight of a rigid airship over Lake Constance.
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
-
Monday
January 1, 1900
- Ended on
-
Monday
December 31, 1900
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Easter Sunday
-
April 15
Sunday, April 15, 1900
- Decade
-
1900s
1900–1909
- Century
-
19th century
1801–1900
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
126
126 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
-
5660 / 5661 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1317 / 1318 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
-
2443 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1278 / 1279 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1892 / 1893 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1822 / 1821 Saka
Indian national calendar; year starts in March.
- Japanese
-
Meiji 33
Reign-era counting from the start of each emperor's reign.
Properties
- Parity
- Even
- Digit count
- 4
- Digit sum
- 10
- Digit product
- 0
- Digital root
- 1
- Palindrome
- No
- Bit width
- 11 bits
- Reversed
- 91
- Flips to (rotate 180°)
- 61
- Recamán's sequence
- a(7,944) = 1,900
- Square (n²)
- 3,610,000
- Cube (n³)
- 6,859,000,000
- Divisor count
- 18
- σ(n) — sum of divisors
- 4,340
- φ(n) — Euler's totient
- 720
- Sum of prime factors
- 33
Primality
Prime factorization: 2 2 × 5 2 × 19
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√1,900 = [43; (1, 1, 2, 3, 4, 3, 2, 1, 1, 86)]
Period length 10 — the block in parentheses repeats forever.
Representations
- In words
- one thousand nine hundred
- Ordinal
- 1900th
- Roman numeral
- MCM
- Binary
- 11101101100
- Octal
- 3554
- Hexadecimal
- 0x76C
- Base64
- B2w=
- One's complement
- 63,635 (16-bit)
- Scientific notation
- 1.9 × 10³
- As a duration
- 1,900 s = 31 minutes, 40 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹 𒌋𒌋𒌋𒌋
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢
- Greek (Milesian)
- ͵αϡʹ
- Mayan (base 20)
- 𝋤·𝋯·𝋠
- Chinese
- 一千九百
- Chinese (financial)
- 壹仟玖佰
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,900 = 6
- e — Euler's number (e)
- Digit 1,900 = 6
- φ — Golden ratio (φ)
- Digit 1,900 = 0
- √2 — Pythagoras's (√2)
- Digit 1,900 = 1
- ln 2 — Natural log of 2
- Digit 1,900 = 3
- γ — Euler-Mascheroni (γ)
- Digit 1,900 = 1
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1900, here are decompositions:
- 11 + 1889 = 1900
- 23 + 1877 = 1900
- 29 + 1871 = 1900
- 53 + 1847 = 1900
- 89 + 1811 = 1900
- 113 + 1787 = 1900
- 167 + 1733 = 1900
- 179 + 1721 = 1900
Showing the first eight; more decompositions exist.
UTF-8 encoding: DD AC (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.108.
- Address
- 0.0.7.108
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.7.108
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 1,900 Hz is closest to:
- Concert pitch (A4 = 440 Hz): A♯6 (1864.7 Hz, +33¢)
- Scientific pitch (C4 = 256 Hz): B6 (1933.1 Hz, -30¢)
- Baroque pitch (A4 = 415 Hz): B6 (1863.3 Hz, +34¢)
The digit sequence 1900 first appears in π at position 4,791 of the decimal expansion (the 4,791ordinal-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.
Related reading
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.