number.wiki
Number

1,642

1,642 is a composite number, even, a calendar year.

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

Notable events — 1642 AD

  1. Aug 22 Charles I raises his standard at Nottingham, beginning the English Civil War.
  2. Oct 23 The first major battle of the war is fought at Edgehill.
  3. Dec 13 Abel Tasman becomes the first European to reach New Zealand.

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
Wednesday
January 1, 1642
Ended on
Wednesday
December 31, 1642
Friday the 13ths
1
One Friday the 13th this year.
Easter Sunday
April 20
Sunday, April 20, 1642
Decade
1640s
1640–1649
Century
17th century
1601–1700
Millennium
2nd millennium
1001–2000
Years ago
384
384 years before 2026.

In other calendars

Hebrew
5402 / 5403 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
1051 / 1052 AH
Lunar calendar; year spans differ from Gregorian.
Chinese
Year of the zodiac:Water zodiac:Horse
Sexagenary cycle position 19 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era
2185 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
1020 / 1021 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
1634 / 1635 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
1564 / 1563 Saka
Indian national calendar; year starts in March.

Properties

Parity
Even
Digit count
4
Digit sum
13
Digit product
48
Digital root
4
Palindrome
No
Bit width
11 bits
Reversed
2,461
Recamán's sequence
a(30,264) = 1,642
Square (n²)
2,696,164
Cube (n³)
4,427,101,288
Divisor count
4
σ(n) — sum of divisors
2,466
φ(n) — Euler's totient
820
Sum of prime factors
823

Primality

Prime factorization: 2 × 821

Nearest primes: 1,637 (−5) · 1,657 (+15)

Divisors & multiples

All divisors (4)
1 · 2 · 821 (half) · 1642
Aliquot sum (sum of proper divisors): 824
Factor pairs (a × b = 1,642)
1 × 1642
2 × 821
First multiples
1,642 · 3,284 (double) · 4,926 · 6,568 · 8,210 · 9,852 · 11,494 · 13,136 · 14,778 · 16,420

Sums & aliquot sequence

As a sum of two squares: 11² + 39²
As consecutive integers: 409 + 410 + 411 + 412
Aliquot sequence: 1,642 824 736 776 694 350 394 200 265 59 1 0 — terminates at zero

Representations

In words
one thousand six hundred forty-two
Ordinal
1642nd
Roman numeral
MDCXLII
Binary
11001101010
Octal
3152
Hexadecimal
0x66A
Base64
Bmo=
One's complement
63,893 (16-bit)
In other bases
ternary (3) 2020211
quaternary (4) 121222
quinary (5) 23032
senary (6) 11334
septenary (7) 4534
nonary (9) 2224
undecimal (11) 1263
duodecimal (12) b4a
tridecimal (13) 994
tetradecimal (14) 854
pentadecimal (15) 747

Historical numeral systems

Babylonian (base 60)
𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹𒁹
Egyptian hieroglyphic
𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓏺𓏺
Greek (Milesian)
͵αχμβʹ
Mayan (base 20)
𝋤·𝋢·𝋢
Chinese
一千六百四十二
Chinese (financial)
壹仟陸佰肆拾貳
In other modern scripts
Eastern Arabic ١٦٤٢ Devanagari १६४२ Bengali ১৬৪২ Tamil ௧௬௪௨ Thai ๑๖๔๒ Tibetan ༡༦༤༢ Khmer ១៦៤២ Lao ໑໖໔໒ Burmese ၁၆၄၂

Digit at this position in famous constants

π — Pi (π)
Digit 1,642 = 1
e — Euler's number (e)
Digit 1,642 = 7
φ — Golden ratio (φ)
Digit 1,642 = 5
√2 — Pythagoras's (√2)
Digit 1,642 = 8
ln 2 — Natural log of 2
Digit 1,642 = 7
γ — Euler-Mascheroni (γ)
Digit 1,642 = 7

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1642, here are decompositions:

  • 5 + 1637 = 1642
  • 23 + 1619 = 1642
  • 29 + 1613 = 1642
  • 41 + 1601 = 1642
  • 59 + 1583 = 1642
  • 71 + 1571 = 1642
  • 83 + 1559 = 1642
  • 89 + 1553 = 1642

Showing the first eight; more decompositions exist.

Unicode codepoint
٪
Arabic Percent Sign
U+066A
Other punctuation (Po)

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

Hex color
#00066A
RGB(0, 6, 106)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.106.

Address
0.0.6.106
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.6.106

Unspecified address (0.0.0.0/8) — "this network" placeholder.

Position in π

The digit sequence 1642 first appears in π at position 992 of the decimal expansion (the 992ordinal-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.