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Number

1,641

1,641 is a composite number, odd, a calendar year.

Arithmetic Number Deficient Number Evil Number Recamán's Sequence Semiprime Squarefree Year

Notable events — 1641 AD

  1. Oct 23 The Irish Rebellion of 1641 erupts.
  2. May 12 Charles I signs the death warrant of his minister Strafford.
  3. 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

Parity
Odd
Digit count
4
Digit sum
12
Digit product
24
Digital root
3
Palindrome
No
Bit width
11 bits
Reversed
1,461
Recamán's sequence
a(1,298) = 1,641
Square (n²)
2,692,881
Cube (n³)
4,419,017,721
Divisor count
4
σ(n) — sum of divisors
2,192
φ(n) — Euler's totient
1,092
Sum of prime factors
550

Primality

Prime factorization: 3 × 547

Nearest primes: 1,637 (−4) · 1,657 (+16)

Divisors & multiples

All divisors (4)
1 · 3 · 547 · 1641
Aliquot sum (sum of proper divisors): 551
Factor pairs (a × b = 1,641)
1 × 1641
3 × 547
First multiples
1,641 · 3,282 (double) · 4,923 · 6,564 · 8,205 · 9,846 · 11,487 · 13,128 · 14,769 · 16,410

Sums & aliquot sequence

As consecutive integers: 820 + 821 546 + 547 + 548 271 + 272 + 273 + 274 + 275 + 276
Aliquot sequence: 1,641 551 49 8 7 1 0 — terminates at zero

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)
In other bases
ternary (3) 2020210
quaternary (4) 121221
quinary (5) 23031
senary (6) 11333
septenary (7) 4533
nonary (9) 2223
undecimal (11) 1262
duodecimal (12) b49
tridecimal (13) 993
tetradecimal (14) 853
pentadecimal (15) 746

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
In other modern scripts
Eastern Arabic ١٦٤١ Devanagari १६४१ Bengali ১৬৪১ Tamil ௧௬௪௧ Thai ๑๖๔๑ Tibetan ༡༦༤༡ Khmer ១៦៤១ Lao ໑໖໔໑ Burmese ၁၆၄၁

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

Unicode codepoint
٩
Arabic-Indic Digit Nine
U+0669
Decimal digit (Nd)

UTF-8 encoding: D9 A9 (2 bytes).

Hex color
#000669
RGB(0, 6, 105)
IPv4 address

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.

Position in π

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.