Live analysis

3,991

3,991 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.).

Arithmetic Number Deficient Number Odious Number Recamán's Sequence Semiprime Squarefree

Properties

Parity: Odd
Digit count: 4
Digit sum: 22
Digit product: 243
Digital root: 4
Palindrome: No
Bit width: 12 bits
Reversed: 1,993
Recamán's sequence: a(14,409) = 3,991
Square (n²): 15,928,081
Cube (n³): 63,568,971,271
Divisor count: 4
σ(n) — sum of divisors: 4,312
φ(n) — Euler's totient: 3,672
Sum of prime factors: 320

Primality

Prime factorization: 13 × 307

Nearest primes: 3,989 (−2) · 4,001 (+10)

Divisors & multiples

All divisors (4)

1 · 13 · 307 · 3991

Aliquot sum (sum of proper divisors): 321

Factor pairs (a × b = 3,991)

1 × 3991

13 × 307

First multiples

3,991 · 7,982 (double) · 11,973 · 15,964 · 19,955 · 23,946 · 27,937 · 31,928 · 35,919 · 39,910

Sums & aliquot sequence

As consecutive integers: 1,995 + 1,996 301 + 302 + … + 313 141 + 142 + … + 166

Aliquot sequence: 3,991 → 321 → 111 → 41 → 1 → 0 — terminates at zero

Representations

In words: three thousand nine hundred ninety-one
Ordinal: 3991st
Roman numeral: MMMCMXCI
Binary: 111110010111
Octal: 7627
Hexadecimal: 0xF97
Base64: D5c=
One's complement: 61,544 (16-bit)

In other bases

ternary (3) 12110211

quaternary (4) 332113

quinary (5) 111431

senary (6) 30251

septenary (7) 14431

nonary (9) 5424

undecimal (11) 2aa9

duodecimal (12) 2387

tridecimal (13) 1a80

tetradecimal (14) 1651

pentadecimal (15) 12b1

Historical numeral systems

Babylonian (base 60): 𒁹 𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian): ͵γϡϟαʹ
Mayan (base 20): 𝋩·𝋳·𝋫
Chinese: 三千九百九十一
Chinese (financial): 參仟玖佰玖拾壹

In other modern scripts

Eastern Arabic ٣٩٩١ Devanagari ३९९१ Bengali ৩৯৯১ Tamil ௩௯௯௧ Thai ๓๙๙๑ Tibetan ༣༩༩༡ Khmer ៣៩៩១ Lao ໓໙໙໑ Burmese ၃၉၉၁

Digit at this position in famous constants

π — Pi (π): Digit 3,991 = 7
e — Euler's number (e): Digit 3,991 = 4
φ — Golden ratio (φ): Digit 3,991 = 1
√2 — Pythagoras's (√2): Digit 3,991 = 5
ln 2 — Natural log of 2: Digit 3,991 = 7
γ — Euler-Mascheroni (γ): Digit 3,991 = 0

Also seen as

Unicode codepoint

ྗ

Tibetan Subjoined Letter Ja

U+0F97

Non-spacing mark (Mn)

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

Lookup U+0F97 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000F97

RGB(0, 15, 151)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.15.151.

Address: 0.0.15.151
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.15.151

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

Position in π

The digit sequence 3991 first appears in π at position 13,015 of the decimal expansion (the 13,015ordinal-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 3991 on Pi Search ↗