1,664
1,664 is a composite number, even, a calendar year.
Notable events — 1664 AD
- Aug 27 The Dutch surrender New Amsterdam to the English; it is renamed New York.
- Aug 1 Ottoman forces are checked at St. Gotthard, ending their westward advance.
- Dec 17 An English fleet seizes Dutch posts on the African coast, escalating to war.
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
-
Tuesday
January 1, 1664
- Ended on
-
Wednesday
December 31, 1664
- Friday the 13ths
-
1
One Friday the 13th this year.
- Easter Sunday
-
April 13
Sunday, April 13, 1664
- Decade
-
1660s
1660–1669
- Century
-
17th century
1601–1700
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
362
362 years before 2026.
In other calendars
- Hebrew
-
5424 / 5425 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1074 / 1075 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Wood zodiac:Dragon
Sexagenary cycle position 41 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
2207 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1042 / 1043 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1656 / 1657 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1586 / 1585 Saka
Indian national calendar; year starts in March.
Properties
- Parity
- Even
- Digit count
- 4
- Digit sum
- 17
- Digit product
- 144
- Digital root
- 8
- Palindrome
- No
- Bit width
- 11 bits
- Reversed
- 4,661
- Recamán's sequence
- a(796) = 1,664
- Square (n²)
- 2,768,896
- Cube (n³)
- 4,607,442,944
- Divisor count
- 16
- σ(n) — sum of divisors
- 3,570
- φ(n) — Euler's totient
- 768
- Sum of prime factors
- 27
Primality
Prime factorization: 2 7 × 13
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand six hundred sixty-four
- Ordinal
- 1664th
- Roman numeral
- MDCLXIV
- Binary
- 11010000000
- Octal
- 3200
- Hexadecimal
- 0x680
- Base64
- BoA=
- One's complement
- 63,871 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵αχξδʹ
- Mayan (base 20)
- 𝋤·𝋣·𝋤
- Chinese
- 一千六百六十四
- Chinese (financial)
- 壹仟陸佰陸拾肆
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,664 = 5
- e — Euler's number (e)
- Digit 1,664 = 6
- φ — Golden ratio (φ)
- Digit 1,664 = 6
- √2 — Pythagoras's (√2)
- Digit 1,664 = 4
- ln 2 — Natural log of 2
- Digit 1,664 = 0
- γ — Euler-Mascheroni (γ)
- Digit 1,664 = 8
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1664, here are decompositions:
- 7 + 1657 = 1664
- 37 + 1627 = 1664
- 43 + 1621 = 1664
- 67 + 1597 = 1664
- 97 + 1567 = 1664
- 181 + 1483 = 1664
- 193 + 1471 = 1664
- 211 + 1453 = 1664
Showing the first eight; more decompositions exist.
UTF-8 encoding: DA 80 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.128.
- Address
- 0.0.6.128
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.6.128
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1664 first appears in π at position 4,742 of the decimal expansion (the 4,742ordinal-suffix:nd 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.