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Number

981

981 is a composite number, odd, a calendar year.

Deficient Number Descending Digits Flippable Odious Number Pernicious Number Recamán's Sequence Year

Historical context — 981 AD

Calendar year

Year 981 (CMLXXXI) was a common year starting on Saturday of the Julian calendar.

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Historical context — 981 BC

Decade

The 980s BC is a decade that lasted from 989 BC to 980 BC.

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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, 981
Ended on
Monday
December 31, 981
Friday the 13ths
2
2 Friday the 13ths this year.
Decade
980s
980–989
Century
10th century
901–1000
Millennium
1st millennium
1–1000
Years ago
1,045
1045 years before 2026.

In other calendars

Hebrew
4741 / 4742 AM
Rosh Hashanah falls in September/October.
Islamic Hijri
370 / 371 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
1524 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri
359 / 360 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian
973 / 974 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka)
903 / 902 Saka
Indian national calendar; year starts in March.

Properties

Parity
Odd
Digit count
3
Digit sum
18
Digit product
72
Digital root
9
Palindrome
No
Bit width
10 bits
Reversed
189
Flips to (rotate 180°)
186
Recamán's sequence
a(4,457) = 981
Square (n²)
962,361
Cube (n³)
944,076,141
Divisor count
6
σ(n) — sum of divisors
1,430
φ(n) — Euler's totient
648
Sum of prime factors
115

Primality

Prime factorization: 3 2 × 109

Nearest primes: 977 (−4) · 983 (+2)

Divisors & multiples

All divisors (6)
1 · 3 · 9 · 109 · 327 · 981
Aliquot sum (sum of proper divisors): 449
Factor pairs (a × b = 981)
1 × 981
3 × 327
9 × 109
First multiples
981 · 1,962 (double) · 2,943 · 3,924 · 4,905 · 5,886 · 6,867 · 7,848 · 8,829 · 9,810

Sums & aliquot sequence

As a sum of two squares: 9² + 30²
As consecutive integers: 490 + 491 326 + 327 + 328 161 + 162 + 163 + 164 + 165 + 166 105 + 106 + … + 113
Aliquot sequence: 981 449 1 0 — terminates at zero

Representations

In words
nine hundred eighty-one
Ordinal
981st
Roman numeral
CMLXXXI
Binary
1111010101
Octal
1725
Hexadecimal
0x3D5
Base64
A9U=
One's complement
64,554 (16-bit)
In other bases
ternary (3) 1100100
quaternary (4) 33111
quinary (5) 12411
senary (6) 4313
septenary (7) 2601
nonary (9) 1310
undecimal (11) 812
duodecimal (12) 699
tridecimal (13) 5a6
tetradecimal (14) 501
pentadecimal (15) 456

Historical numeral systems

Babylonian (base 60)
𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹
Egyptian hieroglyphic
𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian)
ϡπαʹ
Mayan (base 20)
𝋢·𝋩·𝋡
Chinese
九百八十一
Chinese (financial)
玖佰捌拾壹
In other modern scripts
Eastern Arabic ٩٨١ Devanagari ९८१ Bengali ৯৮১ Tamil ௯௮௧ Thai ๙๘๑ Tibetan ༩༨༡ Khmer ៩៨១ Lao ໙໘໑ Burmese ၉၈၁

Digit at this position in famous constants

π — Pi (π)
Digit 981 = 7
e — Euler's number (e)
Digit 981 = 2
φ — Golden ratio (φ)
Digit 981 = 2
√2 — Pythagoras's (√2)
Digit 981 = 5
ln 2 — Natural log of 2
Digit 981 = 2
γ — Euler-Mascheroni (γ)
Digit 981 = 6

Also seen as

Unicode codepoint
ϕ
Greek Phi Symbol
U+03D5
Lowercase letter (Ll)

UTF-8 encoding: CF 95 (2 bytes).

Hex color
#0003D5
RGB(0, 3, 213)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.3.213.

Address
0.0.3.213
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.3.213

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