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Number

1,001

1,001 is a composite number, odd, a calendar year.

Arithmetic Number Deficient Number Flippable Gapful Number Odious Number Palindrome Pentagonal Pernicious Number Recamán's Sequence Sphenic Number Squarefree Strobogrammatic Year

Historical context — 1001 AD

Calendar year

1001 (MI) was a common year starting on Wednesday of the Julian calendar, the 1001st year of the Common Era (CE) and Anno Domini (AD) designations, the 1st year of the 2nd millennium and the 11th century, and the 2nd year of the 1000s decade.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback Read the full article on Wikipedia →

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
53
Long year: contains 53 ISO weeks.
Started on
Thursday
January 1, 1001
Ended on
Thursday
December 31, 1001
Friday the 13ths
3
3 Friday the 13ths this year.
Decade
1000s
1000–1009
Century
11th century
1001–1100
Millennium
2nd millennium
1001–2000
Years ago
1,025
1025 years before 2026.

In other calendars

Hebrew
4761 / 4762 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
391 / 392 AH
Lunar calendar; year spans differ from Gregorian.
Chinese
Year of the zodiac:Metal zodiac:Ox
Sexagenary cycle position 38 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era
1544 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
379 / 380 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
993 / 994 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
923 / 922 Saka
Indian national calendar; year starts in March.

Properties

Parity
Odd
Digit count
4
Digit sum
2
Digit product
0
Digital root
2
Palindrome
Yes
Bit width
10 bits
Recamán's sequence
a(4,417) = 1,001
Square (n²)
1,002,001
Cube (n³)
1,003,003,001
Divisor count
8
σ(n) — sum of divisors
1,344
φ(n) — Euler's totient
720
Sum of prime factors
31

Primality

Prime factorization: 7 × 11 × 13

Nearest primes: 997 (−4) · 1,009 (+8)

Divisors & multiples

All divisors (8)
1 · 7 · 11 · 13 · 77 · 91 · 143 · 1001
Aliquot sum (sum of proper divisors): 343
Factor pairs (a × b = 1,001)
1 × 1001
7 × 143
11 × 91
13 × 77
First multiples
1,001 · 2,002 (double) · 3,003 · 4,004 · 5,005 · 6,006 · 7,007 · 8,008 · 9,009 · 10,010

Sums & aliquot sequence

As consecutive integers: 500 + 501 140 + 141 + … + 146 86 + 87 + … + 96 71 + 72 + … + 83
Aliquot sequence: 1,001 343 57 23 1 0 — terminates at zero

Representations

In words
one thousand one
Ordinal
1001st
Roman numeral
MI
Binary
1111101001
Octal
1751
Hexadecimal
0x3E9
Base64
A+k=
One's complement
64,534 (16-bit)
In other bases
ternary (3) 1101002
quaternary (4) 33221
quinary (5) 13001
senary (6) 4345
septenary (7) 2630
nonary (9) 1332
undecimal (11) 830
duodecimal (12) 6b5
tridecimal (13) 5c0
tetradecimal (14) 517
pentadecimal (15) 46b

Historical numeral systems

Babylonian (base 60)
𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓆼𓏺
Greek (Milesian)
͵ααʹ
Mayan (base 20)
𝋢·𝋪·𝋡
Chinese
一千零一
Chinese (financial)
壹仟零壹
In other modern scripts
Eastern Arabic ١٠٠١ Devanagari १००१ Bengali ১০০১ Tamil ௧௦௦௧ Thai ๑๐๐๑ Tibetan ༡༠༠༡ Khmer ១០០១ Lao ໑໐໐໑ Burmese ၁၀၀၁

Digit at this position in famous constants

π — Pi (π)
Digit 1,001 = 9
e — Euler's number (e)
Digit 1,001 = 4
φ — Golden ratio (φ)
Digit 1,001 = 2
√2 — Pythagoras's (√2)
Digit 1,001 = 2
ln 2 — Natural log of 2
Digit 1,001 = 7
γ — Euler-Mascheroni (γ)
Digit 1,001 = 2

Also seen as

Unicode codepoint
ϩ
Coptic Small Letter Hori
U+03E9
Lowercase letter (Ll)

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

Hex color
#0003E9
RGB(0, 3, 233)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.233.

Address
0.0.3.233
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.3.233

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

Position in π

The digit sequence 1001 first appears in π at position 15,761 of the decimal expansion (the 15,761ordinal-suffix:st 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.