1,646
1,646 is a composite number, even, a calendar year.
Notable events — 1646 AD
- May 5 Charles I surrenders to Scottish forces.
- Mar 26 The First English Civil War effectively ends.
- Sep 16 The siege of Dunkirk ends with a French victory.
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
-
Monday
January 1, 1646
- Ended on
-
Monday
December 31, 1646
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Easter Sunday
-
April 1
Sunday, April 1, 1646
- Decade
-
1640s
1640–1649
- Century
-
17th century
1601–1700
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
380
380 years before 2026.
In other calendars
- Hebrew
-
5406 / 5407 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1055 / 1056 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Fire zodiac:Dog
Sexagenary cycle position 23 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
2189 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1024 / 1025 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1638 / 1639 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1568 / 1567 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
- 6,461
- Recamán's sequence
- a(764) = 1,646
- Square (n²)
- 2,709,316
- Cube (n³)
- 4,459,534,136
- Divisor count
- 4
- σ(n) — sum of divisors
- 2,472
- φ(n) — Euler's totient
- 822
- Sum of prime factors
- 825
Primality
Prime factorization: 2 × 823
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- one thousand six hundred forty-six
- Ordinal
- 1646th
- Roman numeral
- MDCXLVI
- Binary
- 11001101110
- Octal
- 3156
- Hexadecimal
- 0x66E
- Base64
- Bm4=
- One's complement
- 63,889 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵αχμϛʹ
- Mayan (base 20)
- 𝋤·𝋢·𝋦
- Chinese
- 一千六百四十六
- Chinese (financial)
- 壹仟陸佰肆拾陸
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,646 = 5
- e — Euler's number (e)
- Digit 1,646 = 9
- φ — Golden ratio (φ)
- Digit 1,646 = 8
- √2 — Pythagoras's (√2)
- Digit 1,646 = 5
- ln 2 — Natural log of 2
- Digit 1,646 = 7
- γ — Euler-Mascheroni (γ)
- Digit 1,646 = 3
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1646, here are decompositions:
- 19 + 1627 = 1646
- 37 + 1609 = 1646
- 67 + 1579 = 1646
- 79 + 1567 = 1646
- 97 + 1549 = 1646
- 103 + 1543 = 1646
- 157 + 1489 = 1646
- 163 + 1483 = 1646
Showing the first eight; more decompositions exist.
UTF-8 encoding: D9 AE (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.110.
- Address
- 0.0.6.110
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.6.110
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 1646 first appears in π at position 9,635 of the decimal expansion (the 9,635ordinal-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.