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Number

2,689

2,689 is a prime, odd.

2,689 (two thousand six hundred eighty-nine) is an odd 4-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is MMDCLXXXIX and in binary, 101010000001.

Arithmetic Number Ascending Digits Cousin Prime Cube-Free Deficient Number Evil Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Squarefree Twin Prime

Interestingness

10 notable facts · grade A
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Properties

Parity
Odd
Digit count
4
Digit sum
25
Digit product
864
Digital root
7
Palindrome
No
Bit width
12 bits
Reversed
9,862
Recamán's sequence
a(993) = 2,689
Square (n²)
7,230,721
Cube (n³)
19,443,408,769
Divisor count
2
σ(n) — sum of divisors
2,690
φ(n) — Euler's totient
2,688

Primality

2,689 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 2689
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 2,689)
1 × 2689
First multiples
2,689 · 5,378 (double) · 8,067 · 10,756 · 13,445 · 16,134 · 18,823 · 21,512 · 24,201 · 26,890

Sums & aliquot sequence

As a sum of two squares: 33² + 40²
As consecutive integers: 1,344 + 1,345

Continued fraction of √n

√2,689 = [51; (1, 5, 1, 12, 9, 2, 1, 5, 1, 4, 11, 3, 6, 1, 1, 2, 3, 1, 3, 14, 1, 1, 4, 2, …)]

Representations

In words
two thousand six hundred eighty-nine
Ordinal
2689th
Roman numeral
MMDCLXXXIX
Binary
101010000001
Octal
5201
Hexadecimal
0xA81
Base64
CoE=
One's complement
62,846 (16-bit)
Scientific notation
2.689 × 10³
As a duration
2,689 s = 44 minutes, 49 seconds
In other bases
ternary (3) 10200121
quaternary (4) 222001
quinary (5) 41224
senary (6) 20241
septenary (7) 10561
nonary (9) 3617
undecimal (11) 2025
duodecimal (12) 1681
tridecimal (13) 12bb
tetradecimal (14) da1
pentadecimal (15) be4

As an angle

2,689° = 7 × 360° + 169°
169° ≈ 2.95 rad
Compass bearing: S (south)

Historical numeral systems

Babylonian (base 60)
𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic
𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian)
͵βχπθʹ
Mayan (base 20)
𝋦·𝋮·𝋩
Chinese
二千六百八十九
Chinese (financial)
貳仟陸佰捌拾玖
In other modern scripts
Eastern Arabic ٢٦٨٩ Devanagari २६८९ Bengali ২৬৮৯ Tamil ௨௬௮௯ Thai ๒๖๘๙ Tibetan ༢༦༨༩ Khmer ២៦៨៩ Lao ໒໖໘໙ Burmese ၂၆၈၉

Digit at this position in famous constants

π — Pi (π)
Digit 2,689 = 1
e — Euler's number (e)
Digit 2,689 = 7
φ — Golden ratio (φ)
Digit 2,689 = 6
√2 — Pythagoras's (√2)
Digit 2,689 = 9
ln 2 — Natural log of 2
Digit 2,689 = 1
γ — Euler-Mascheroni (γ)
Digit 2,689 = 4

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 2,687 (gap of 2)
  • Next prime: 2,693 (gap of 4)

Pair status: twin with 2687, cousin with 2693.

Unicode codepoint
Gujarati Sign Candrabindu
U+0A81
Non-spacing mark (Mn)

UTF-8 encoding: E0 AA 81 (3 bytes).

Hex color
#000A81
RGB(0, 10, 129)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.10.129.

Address
0.0.10.129
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.10.129

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

Musical pitch

Heard as a frequency, 2,689 Hz is closest to:

  • Concert pitch (A4 = 440 Hz): E7 (2637 Hz, +34¢)
  • Scientific pitch (C4 = 256 Hz): F7 (2733.8 Hz, -29¢)
  • Baroque pitch (A4 = 415 Hz): F7 (2635.1 Hz, +35¢)
Position in π

The digit sequence 2689 first appears in π at position 13,112 of the decimal expansion (the 13,112ordinal-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.

Related reading

  • Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
  • Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.