1,915
1,915 is a composite number, odd, a calendar year.
1,915 (one thousand nine hundred fifteen) is an odd 4-digit number. It is a composite number with 4 divisors, and factors as 5 × 383. Written other ways, in Roman numerals it is MCMXV and in binary, 11101111011.
Interestingness
Notable events — 1915 AD
- Apr 22 Germany uses poison gas for the first time on a large scale, at Second Ypres.
- Apr 24 Ottoman authorities arrest Armenian intellectuals in Constantinople, beginning the Armenian Genocide.
- Apr 25 Allied forces land at Gallipoli.
- May 7 A German U-boat sinks the RMS Lusitania off Ireland; 1,198 die.
- Undated Albert Einstein presents the field equations of general relativity to the Prussian Academy in November.
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, 1915
- Ended on
-
Friday
December 31, 1915
- Friday the 13ths
-
1
One Friday the 13th this year.
- Easter Sunday
-
April 4
Sunday, April 4, 1915
- Decade
-
1910s
1910–1919
- Century
-
20th century
1901–2000
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
111
111 years before 2026.
In other calendars
- Hebrew
-
5675 / 5676 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1333 / 1334 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Wood zodiac:Rabbit
Sexagenary cycle position 52 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
2458 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1293 / 1294 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1907 / 1908 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1837 / 1836 Saka
Indian national calendar; year starts in March.
- Japanese
-
Taishō 4
Reign-era counting from the start of each emperor's reign.
Properties
- Parity
- Odd
- Digit count
- 4
- Digit sum
- 16
- Digit product
- 45
- Digital root
- 7
- Palindrome
- No
- Bit width
- 11 bits
- Reversed
- 5,191
- Recamán's sequence
- a(7,914) = 1,915
- Square (n²)
- 3,667,225
- Cube (n³)
- 7,022,735,875
- Divisor count
- 4
- σ(n) — sum of divisors
- 2,304
- φ(n) — Euler's totient
- 1,528
- Sum of prime factors
- 388
Primality
Prime factorization: 5 × 383
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√1,915 = [43; (1, 3, 5, 1, 1, 2, 2, 9, 3, 3, 1, 5, 2, 14, 7, 1, 7, 1, 7, 14, 2, 5, 1, 3, …)]
Period length 34 — the block in parentheses repeats forever.
Representations
- In words
- one thousand nine hundred fifteen
- Ordinal
- 1915th
- Roman numeral
- MCMXV
- Binary
- 11101111011
- Octal
- 3573
- Hexadecimal
- 0x77B
- Base64
- B3s=
- One's complement
- 63,620 (16-bit)
- Scientific notation
- 1.915 × 10³
- As a duration
- 1,915 s = 31 minutes, 55 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵αϡιεʹ
- Mayan (base 20)
- 𝋤·𝋯·𝋯
- Chinese
- 一千九百一十五
- Chinese (financial)
- 壹仟玖佰壹拾伍
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,915 = 9
- e — Euler's number (e)
- Digit 1,915 = 6
- φ — Golden ratio (φ)
- Digit 1,915 = 7
- √2 — Pythagoras's (√2)
- Digit 1,915 = 2
- ln 2 — Natural log of 2
- Digit 1,915 = 5
- γ — Euler-Mascheroni (γ)
- Digit 1,915 = 3
Also seen as
UTF-8 encoding: DD BB (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.123.
- Address
- 0.0.7.123
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.7.123
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 1,915 Hz is closest to:
- Concert pitch (A4 = 440 Hz): A♯6 (1864.7 Hz, +46¢ — about midway to B6)
- Scientific pitch (C4 = 256 Hz): B6 (1933.1 Hz, -16¢)
- Baroque pitch (A4 = 415 Hz): B6 (1863.3 Hz, +47¢ — about midway to C7)
The digit sequence 1915 first appears in π at position 8,846 of the decimal expansion (the 8,846ordinal-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.
Related reading
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.