1,660
1,660 is a composite number, even, a calendar year.
Notable events — 1660 AD
- May 29 Charles II is restored to the English throne.
- Jan 1 Samuel Pepys begins his diary.
- Oct 13 The Royal Society is granted its charter (formally chartered 1662).
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
-
Thursday
January 1, 1660
- Ended on
-
Friday
December 31, 1660
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Easter Sunday
-
March 28
Sunday, March 28, 1660
- Decade
-
1660s
1660–1669
- Century
-
17th century
1601–1700
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
366
366 years before 2026.
In other calendars
- Hebrew
-
5420 / 5421 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1070 / 1071 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
-
2203 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1038 / 1039 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1652 / 1653 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1582 / 1581 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
- 661
- Flips to (rotate 180°)
- 991
- Recamán's sequence
- a(788) = 1,660
- Square (n²)
- 2,755,600
- Cube (n³)
- 4,574,296,000
- Divisor count
- 12
- σ(n) — sum of divisors
- 3,528
- φ(n) — Euler's totient
- 656
- Sum of prime factors
- 92
Primality
Prime factorization: 2 2 × 5 × 83
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand six hundred sixty
- Ordinal
- 1660th
- Roman numeral
- MDCLX
- Binary
- 11001111100
- Octal
- 3174
- Hexadecimal
- 0x67C
- Base64
- Bnw=
- One's complement
- 63,875 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆
- Greek (Milesian)
- ͵αχξʹ
- Mayan (base 20)
- 𝋤·𝋣·𝋠
- Chinese
- 一千六百六十
- Chinese (financial)
- 壹仟陸佰陸拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,660 = 7
- e — Euler's number (e)
- Digit 1,660 = 4
- φ — Golden ratio (φ)
- Digit 1,660 = 4
- √2 — Pythagoras's (√2)
- Digit 1,660 = 4
- ln 2 — Natural log of 2
- Digit 1,660 = 6
- γ — Euler-Mascheroni (γ)
- Digit 1,660 = 7
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1660, here are decompositions:
- 3 + 1657 = 1660
- 23 + 1637 = 1660
- 41 + 1619 = 1660
- 47 + 1613 = 1660
- 53 + 1607 = 1660
- 59 + 1601 = 1660
- 89 + 1571 = 1660
- 101 + 1559 = 1660
Showing the first eight; more decompositions exist.
UTF-8 encoding: D9 BC (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.124.
- Address
- 0.0.6.124
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.6.124
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1660 first appears in π at position 3,994 of the decimal expansion (the 3,994ordinal-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.