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Number

6,991

6,991 is a prime, odd.

Arithmetic Number Deficient Number Flippable Odious Number Prime Recamán's Sequence Sexy Prime Squarefree

Properties

Parity
Odd
Digit count
4
Digit sum
25
Digit product
486
Digital root
7
Palindrome
No
Bit width
13 bits
Reversed
1,996
Flips to (rotate 180°)
1,669
Recamán's sequence
a(177,029) = 6,991
Square (n²)
48,874,081
Cube (n³)
341,678,700,271
Divisor count
2
σ(n) — sum of divisors
6,992
φ(n) — Euler's totient
6,990

Primality

6,991 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 6991
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 6,991)
1 × 6991
First multiples
6,991 · 13,982 (double) · 20,973 · 27,964 · 34,955 · 41,946 · 48,937 · 55,928 · 62,919 · 69,910

Sums & aliquot sequence

As consecutive integers: 3,495 + 3,496

Representations

In words
six thousand nine hundred ninety-one
Ordinal
6991st
Binary
1101101001111
Octal
15517
Hexadecimal
0x1B4F
Base64
G08=
One's complement
58,544 (16-bit)
In other bases
ternary (3) 100120221
quaternary (4) 1231033
quinary (5) 210431
senary (6) 52211
septenary (7) 26245
nonary (9) 10527
undecimal (11) 5286
duodecimal (12) 4067
tridecimal (13) 324a
tetradecimal (14) 2795
pentadecimal (15) 2111

Historical numeral systems

Babylonian (base 60)
𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
Greek (Milesian)
͵ϛϡϟαʹ
Mayan (base 20)
𝋱·𝋩·𝋫
Chinese
六千九百九十一
Chinese (financial)
陸仟玖佰玖拾壹
In other modern scripts
Eastern Arabic ٦٩٩١ Devanagari ६९९१ Bengali ৬৯৯১ Tamil ௬௯௯௧ Thai ๖๙๙๑ Tibetan ༦༩༩༡ Khmer ៦៩៩១ Lao ໖໙໙໑ Burmese ၆၉၉၁

Digit at this position in famous constants

π — Pi (π)
Digit 6,991 = 2
e — Euler's number (e)
Digit 6,991 = 3
φ — Golden ratio (φ)
Digit 6,991 = 5
√2 — Pythagoras's (√2)
Digit 6,991 = 9
ln 2 — Natural log of 2
Digit 6,991 = 3
γ — Euler-Mascheroni (γ)
Digit 6,991 = 6

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 6,983 (gap of 8)
  • Next prime: 6,997 (gap of 6)

Pair status: sexy with 6997.

Unicode codepoint
Balinese Inverted Carik Pareren
U+1B4F
Other punctuation (Po)

UTF-8 encoding: E1 AD 8F (3 bytes).

Hex color
#001B4F
RGB(0, 27, 79)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.27.79.

Address
0.0.27.79
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.27.79

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

Position in π

The digit sequence 6991 first appears in π at position 10,760 of the decimal expansion (the 10,760ordinal-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.