1,815
1,815 is a composite number, odd, a calendar year.
Notable events — 1815 AD
- Mar 20 Napoleon returns to Paris from Elba, beginning the Hundred Days.
- Apr 10 Mount Tambora in Indonesia erupts, the largest eruption in recorded history.
- Jun 18 Wellington and Blücher defeat Napoleon at Waterloo.
- Jun 22 Napoleon abdicates a second time; he is exiled to St. Helena.
- Jun 9 The Congress of Vienna concludes, reshaping Europe.
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
-
Sunday
January 1, 1815
- Ended on
-
Sunday
December 31, 1815
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Easter Sunday
-
March 26
Sunday, March 26, 1815
- Decade
-
1810s
1810–1819
- Century
-
19th century
1801–1900
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
211
211 years before 2026.
In other calendars
- Hebrew
-
5575 / 5576 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1230 / 1231 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Wood zodiac:Pig
Sexagenary cycle position 12 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
2358 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1193 / 1194 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1807 / 1808 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1737 / 1736 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Odd
- Digit count
- 4
- Digit sum
- 15
- Digit product
- 40
- Digital root
- 6
- Palindrome
- No
- Bit width
- 11 bits
- Reversed
- 5,181
- Recamán's sequence
- a(453) = 1,815
- Square (n²)
- 3,294,225
- Cube (n³)
- 5,979,018,375
- Divisor count
- 12
- σ(n) — sum of divisors
- 3,192
- φ(n) — Euler's totient
- 880
- Sum of prime factors
- 30
Primality
Prime factorization: 3 × 5 × 11 2
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand eight hundred fifteen
- Ordinal
- 1815th
- Roman numeral
- MDCCCXV
- Binary
- 11100010111
- Octal
- 3427
- Hexadecimal
- 0x717
- Base64
- Bxc=
- One's complement
- 63,720 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋 𒌋𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵αωιεʹ
- Mayan (base 20)
- 𝋤·𝋪·𝋯
- Chinese
- 一千八百一十五
- Chinese (financial)
- 壹仟捌佰壹拾伍
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,815 = 5
- e — Euler's number (e)
- Digit 1,815 = 5
- φ — Golden ratio (φ)
- Digit 1,815 = 4
- √2 — Pythagoras's (√2)
- Digit 1,815 = 1
- ln 2 — Natural log of 2
- Digit 1,815 = 2
- γ — Euler-Mascheroni (γ)
- Digit 1,815 = 8
Also seen as
UTF-8 encoding: DC 97 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.7.23.
- Address
- 0.0.7.23
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.7.23
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1815 first appears in π at position 728 of the decimal expansion (the 728ordinal-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.