Live analysis

2,391

2,391 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.).

2,391 (two thousand three hundred ninety-one) is an odd 4-digit number. It is a composite number with 4 divisors, and factors as 3 × 797. Written other ways, in Roman numerals it is MMCCCXCI and in binary, 100101010111.

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

Interestingness

★ ★ ★ ★ ☆

6 notable facts · grade B

2,379 2,380 2,381 2,382 2,383 2,384 2,385 2,386 2,387 2,388 2,389 2,390 2,391 2,392 2,393 2,394 2,395 2,396 2,397 2,398 2,399 2,400 2,401 2,402 2,403

less more

Properties

Parity: Odd
Digit count: 4
Digit sum: 15
Digit product: 54
Digital root: 6
Palindrome: No
Bit width: 12 bits
Reversed: 1,932
Recamán's sequence: a(98,690) = 2,391
Square (n²): 5,716,881
Cube (n³): 13,669,062,471
Divisor count: 4
σ(n) — sum of divisors: 3,192
φ(n) — Euler's totient: 1,592
Sum of prime factors: 800

Primality

Prime factorization: 3 × 797

Nearest primes: 2,389 (−2) · 2,393 (+2)

Divisors & multiples

All divisors (4)

1 · 3 · 797 · 2391

Aliquot sum (sum of proper divisors): 801

Factor pairs (a × b = 2,391)

1 × 2391

3 × 797

First multiples

2,391 · 4,782 (double) · 7,173 · 9,564 · 11,955 · 14,346 · 16,737 · 19,128 · 21,519 · 23,910

Sums & aliquot sequence

As consecutive integers: 1,195 + 1,196 796 + 797 + 798 396 + 397 + 398 + 399 + 400 + 401

Aliquot sequence: 2,391 → 801 → 369 → 177 → 63 → 41 → 1 → 0 — terminates at zero

Continued fraction of √n

√2,391 = [48; (1, 8, 1, 3, 1, 3, 8, 1, 1, 1, 2, 7, 6, 1, 5, 1, 1, 1, 15, 1, 1, 1, 5, 1, …)]

Period length 38 — the block in parentheses repeats forever.

Representations

In words: two thousand three hundred ninety-one
Ordinal: 2391st
Roman numeral: MMCCCXCI
Binary: 100101010111
Octal: 4527
Hexadecimal: 0x957
Base64: CVc=
One's complement: 63,144 (16-bit)
Scientific notation: 2.391 × 10³
As a duration: 2,391 s = 39 minutes, 51 seconds

In other bases

ternary (3) 10021120

quaternary (4) 211113

quinary (5) 34031

senary (6) 15023

septenary (7) 6654

nonary (9) 3246

undecimal (11) 1884

duodecimal (12) 1473

tridecimal (13) 111c

tetradecimal (14) c2b

pentadecimal (15) a96

As an angle

2,391° = 6 × 360° + 231°

231° ≈ 4.032 rad

Compass bearing: SW (southwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓆼𓆼𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): ͵βτϟαʹ
Mayan (base 20): 𝋥·𝋳·𝋫
Chinese: 二千三百九十一
Chinese (financial): 貳仟參佰玖拾壹

In other modern scripts

Eastern Arabic ٢٣٩١ Devanagari २३९१ Bengali ২৩৯১ Tamil ௨௩௯௧ Thai ๒๓๙๑ Tibetan ༢༣༩༡ Khmer ២៣៩១ Lao ໒໓໙໑ Burmese ၂၃၉၁

Digit at this position in famous constants

π — Pi (π): Digit 2,391 = 5
e — Euler's number (e): Digit 2,391 = 9
φ — Golden ratio (φ): Digit 2,391 = 0
√2 — Pythagoras's (√2): Digit 2,391 = 8
ln 2 — Natural log of 2: Digit 2,391 = 1
γ — Euler-Mascheroni (γ): Digit 2,391 = 5

Also seen as

Unicode codepoint

ॗ

Devanagari Vowel Sign Uue

U+0957

Non-spacing mark (Mn)

UTF-8 encoding: E0 A5 97 (3 bytes).

Lookup U+0957 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000957

RGB(0, 9, 87)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.9.87.

Address: 0.0.9.87
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.9.87

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

Musical pitch

Heard as a frequency, 2,391 Hz is closest to:

Concert pitch (A4 = 440 Hz): D7 (2349.3 Hz, +30¢)
Scientific pitch (C4 = 256 Hz): D♯7 (2435.5 Hz, -32¢)
Baroque pitch (A4 = 415 Hz): D♯7 (2347.6 Hz, +32¢)

Position in π

The digit sequence 2391 first appears in π at position 3,732 of the decimal expansion (the 3,732ordinal-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.

Look up 2391 on Pi Search ↗