Live analysis

2,981

2,981 is a composite number, odd.

This number doesn't have a permanent NumberWiki page yet — what you see below is computed live. Pages get added to the permanent index when they're notable (years, primes, curated, etc.).

2,981 (two thousand nine hundred eighty-one) is an odd 4-digit number. It is a composite number with 4 divisors, and factors as 11 × 271. Written other ways, in Roman numerals it is MMCMLXXXI and in binary, 101110100101.

Arithmetic Number Cube-Free Deficient Number Odious Number Pernicious Number Recamán's Sequence Semiprime Squarefree

Interestingness

★ ★ ★ ☆ ☆

5 notable facts · grade C

2,969 2,970 2,971 2,972 2,973 2,974 2,975 2,976 2,977 2,978 2,979 2,980 2,981 2,982 2,983 2,984 2,985 2,986 2,987 2,988 2,989 2,990 2,991 2,992 2,993

less more

Properties

Parity: Odd
Digit count: 4
Digit sum: 20
Digit product: 144
Digital root: 2
Palindrome: No
Bit width: 12 bits
Reversed: 1,892
Recamán's sequence: a(2,049) = 2,981
Square (n²): 8,886,361
Cube (n³): 26,490,242,141
Divisor count: 4
σ(n) — sum of divisors: 3,264
φ(n) — Euler's totient: 2,700
Sum of prime factors: 282

Primality

Prime factorization: 11 × 271

Nearest primes: 2,971 (−10) · 2,999 (+18)

Divisors & multiples

All divisors (4)

1 · 11 · 271 · 2981

Aliquot sum (sum of proper divisors): 283

Factor pairs (a × b = 2,981)

1 × 2981

11 × 271

First multiples

2,981 · 5,962 (double) · 8,943 · 11,924 · 14,905 · 17,886 · 20,867 · 23,848 · 26,829 · 29,810

Sums & aliquot sequence

As consecutive integers: 1,490 + 1,491 266 + 267 + … + 276 125 + 126 + … + 146

Aliquot sequence: 2,981 → 283 → 1 → 0 — terminates at zero

Continued fraction of √n

√2,981 = [54; (1, 1, 2, 26, 1, 8, 1, 26, 2, 1, 1, 108)]

Period length 12 — the block in parentheses repeats forever.

Representations

In words: two thousand nine hundred eighty-one
Ordinal: 2981st
Roman numeral: MMCMLXXXI
Binary: 101110100101
Octal: 5645
Hexadecimal: 0xBA5
Base64: C6U=
One's complement: 62,554 (16-bit)
Scientific notation: 2.981 × 10³
As a duration: 2,981 s = 49 minutes, 41 seconds

In other bases

ternary (3) 11002102

quaternary (4) 232211

quinary (5) 43411

senary (6) 21445

septenary (7) 11456

nonary (9) 4072

undecimal (11) 2270

duodecimal (12) 1885

tridecimal (13) 1484

tetradecimal (14) 112d

pentadecimal (15) d3b

As an angle

2,981° = 8 × 360° + 101°

101° ≈ 1.763 rad

Compass bearing: E (east)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): ͵βϡπαʹ
Mayan (base 20): 𝋧·𝋩·𝋡
Chinese: 二千九百八十一
Chinese (financial): 貳仟玖佰捌拾壹

In other modern scripts

Eastern Arabic ٢٩٨١ Devanagari २९८१ Bengali ২৯৮১ Tamil ௨௯௮௧ Thai ๒๙๘๑ Tibetan ༢༩༨༡ Khmer ២៩៨១ Lao ໒໙໘໑ Burmese ၂၉၈၁

Digit at this position in famous constants

π — Pi (π): Digit 2,981 = 7
e — Euler's number (e): Digit 2,981 = 6
φ — Golden ratio (φ): Digit 2,981 = 9
√2 — Pythagoras's (√2): Digit 2,981 = 2
ln 2 — Natural log of 2: Digit 2,981 = 4
γ — Euler-Mascheroni (γ): Digit 2,981 = 3

Also seen as

Hex color

#000BA5

RGB(0, 11, 165)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.11.165.

Address: 0.0.11.165
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.11.165

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

Musical pitch

Heard as a frequency, 2,981 Hz is closest to:

Concert pitch (A4 = 440 Hz): F♯7 (2960 Hz, +12¢)
Scientific pitch (C4 = 256 Hz): F♯7 (2896.3 Hz, +50¢ — about midway to G7)
Baroque pitch (A4 = 415 Hz): G7 (2957.8 Hz, +14¢)

Position in π

The digit sequence 2981 first appears in π at position 11,764 of the decimal expansion (the 11,764ordinal-suffix:th 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.

Look up 2981 on Pi Search ↗