1,680
1,680 is a composite number, even, a calendar year.
Notable events — 1680 AD
- Aug 10 Pueblo Revolt drives Spanish colonists from New Mexico.
- Jul 8 A bright comet (Kirch's) is observed by telescope, the first such discovery.
- Dec 24 King Charles II prorogues Parliament again amid Exclusion strife.
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
- 52
- Started on
-
Monday
January 1, 1680
- Ended on
-
Tuesday
December 31, 1680
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Easter Sunday
-
April 21
Sunday, April 21, 1680
- Decade
-
1680s
1680–1689
- Century
-
17th century
1601–1700
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
346
346 years before 2026.
In other calendars
- Hebrew
-
5440 / 5441 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1090 / 1091 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
-
2223 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1058 / 1059 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1672 / 1673 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1602 / 1601 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Even
- Digit count
- 4
- Digit sum
- 15
- Digit product
- 0
- Digital root
- 6
- Palindrome
- No
- Bit width
- 11 bits
- Reversed
- 861
- Flips to (rotate 180°)
- 891
- Recamán's sequence
- a(828) = 1,680
- Square (n²)
- 2,822,400
- Cube (n³)
- 4,741,632,000
- Divisor count
- 40
- σ(n) — sum of divisors
- 5,952
- φ(n) — Euler's totient
- 384
- Sum of prime factors
- 23
Primality
Prime factorization: 2 4 × 3 × 5 × 7
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand six hundred eighty
- Ordinal
- 1680th
- Roman numeral
- MDCLXXX
- Binary
- 11010010000
- Octal
- 3220
- Hexadecimal
- 0x690
- Base64
- BpA=
- One's complement
- 63,855 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 ·
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆
- Greek (Milesian)
- ͵αχπʹ
- Mayan (base 20)
- 𝋤·𝋤·𝋠
- Chinese
- 一千六百八十
- Chinese (financial)
- 壹仟陸佰捌拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,680 = 6
- e — Euler's number (e)
- Digit 1,680 = 9
- φ — Golden ratio (φ)
- Digit 1,680 = 8
- √2 — Pythagoras's (√2)
- Digit 1,680 = 1
- ln 2 — Natural log of 2
- Digit 1,680 = 1
- γ — Euler-Mascheroni (γ)
- Digit 1,680 = 7
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1680, here are decompositions:
- 11 + 1669 = 1680
- 13 + 1667 = 1680
- 17 + 1663 = 1680
- 23 + 1657 = 1680
- 43 + 1637 = 1680
- 53 + 1627 = 1680
- 59 + 1621 = 1680
- 61 + 1619 = 1680
Showing the first eight; more decompositions exist.
UTF-8 encoding: DA 90 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.144.
- Address
- 0.0.6.144
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.6.144
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1680 first appears in π at position 13,798 of the decimal expansion (the 13,798ordinal-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.