1,641
1,641 is a composite number, odd, a calendar year.
1,641 (one thousand six hundred forty-one) is an odd 4-digit number. It is a composite number with 4 divisors, and factors as 3 × 547. Written other ways, in Roman numerals it is MDCXLI and in binary, 11001101001.
Interestingness
Notable events — 1641 AD
- Oct 23 The Irish Rebellion of 1641 erupts.
- May 12 Charles I signs the death warrant of his minister Strafford.
- Aug 11 Charles I signs the Treaty of London with Scotland.
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
-
Tuesday
January 1, 1641
- Ended on
-
Tuesday
December 31, 1641
- Friday the 13ths
-
2
2 Friday the 13ths this year.
- Easter Sunday
-
March 31
Sunday, March 31, 1641
- Decade
-
1640s
1640–1649
- Century
-
17th century
1601–1700
- Millennium
-
2nd millennium
1001–2000
- Years ago
-
385
385 years before 2026.
In other calendars
- Hebrew
-
5401 / 5402 AM
Rosh Hashanah falls in September/October.
- Islamic Hijri
-
1050 / 1051 AH
Lunar calendar; year spans differ from Gregorian.
- Chinese
-
Year of the zodiac:Metal zodiac:Snake
Sexagenary cycle position 18 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
2184 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Persian Solar Hijri
-
1019 / 1020 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
- Ethiopian
-
1633 / 1634 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
1563 / 1562 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 3 × 547
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√1,641 = [40; (1, 1, 26, 1, 1, 80)]
Period length 6 — the block in parentheses repeats forever.
Representations
- In words
- one thousand six hundred forty-one
- Ordinal
- 1641st
- Roman numeral
- MDCXLI
- Binary
- 11001101001
- Octal
- 3151
- Hexadecimal
- 0x669
- Base64
- Bmk=
- One's complement
- 63,894 (16-bit)
- Scientific notation
- 1.641 × 10³
- As a duration
- 1,641 s = 27 minutes, 21 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵αχμαʹ
- Mayan (base 20)
- 𝋤·𝋢·𝋡
- Chinese
- 一千六百四十一
- Chinese (financial)
- 壹仟陸佰肆拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 1,641 = 4
- e — Euler's number (e)
- Digit 1,641 = 2
- φ — Golden ratio (φ)
- Digit 1,641 = 9
- √2 — Pythagoras's (√2)
- Digit 1,641 = 5
- ln 2 — Natural log of 2
- Digit 1,641 = 8
- γ — Euler-Mascheroni (γ)
- Digit 1,641 = 8
Also seen as
UTF-8 encoding: D9 A9 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.105.
- Address
- 0.0.6.105
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.6.105
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 1,641 Hz is closest to:
- Concert pitch (A4 = 440 Hz): G♯6 (1661.2 Hz, -21¢)
- Scientific pitch (C4 = 256 Hz): G♯6 (1625.5 Hz, +16¢)
- Baroque pitch (A4 = 415 Hz): A6 (1660 Hz, -20¢)
The digit sequence 1641 first appears in π at position 1,422 of the decimal expansion (the 1,422ordinal-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.
Related reading
- Babylonian numerals — The base-60 cuneiform system that gave us 60 minutes, 60 seconds, and 360°.