Live analysis

2,640

2,640 is a composite number, even.

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.).

2,640 (two thousand six hundred forty) is an even 4-digit number. It is a composite number with 40 divisors, and factors as 2⁴ × 3 × 5 × 11. Its proper divisors sum to 6,288, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is MMDCXL and in binary, 101001010000.

Abundant Number Evil Number Gapful Number Harshad / Niven Octagonal Practical Number Recamán's Sequence Refactorable Number Semiperfect Number

Interestingness

★ ★ ★ ★ ☆

7 notable facts · grade B

2,628 2,629 2,630 2,631 2,632 2,633 2,634 2,635 2,636 2,637 2,638 2,639 2,640 2,641 2,642 2,643 2,644 2,645 2,646 2,647 2,648 2,649 2,650 2,651 2,652

less more

Properties

Parity: Even
Digit count: 4
Digit sum: 12
Digit product: 0
Digital root: 3
Palindrome: No
Bit width: 12 bits
Reversed: 462
Recamán's sequence: a(7,352) = 2,640
Square (n²): 6,969,600
Cube (n³): 18,399,744,000
Divisor count: 40
σ(n) — sum of divisors: 8,928
φ(n) — Euler's totient: 640
Sum of prime factors: 27

Primality

Prime factorization: 2 ⁴ × 3 × 5 × 11

Nearest primes: 2,633 (−7) · 2,647 (+7)

Divisors & multiples

All divisors (40)

1 · 2 · 3 · 4 · 5 · 6 · 8 · 10 · 11 · 12 · 15 · 16 · 20 · 22 · 24 · 30 · 33 · 40 · 44 · 48 · 55 · 60 · 66 · 80 · 88 · 110 · 120 · 132 · 165 · 176 · 220 · 240 · 264 · 330 · 440 · 528 · 660 · 880 · 1320 (half) · 2640

Aliquot sum (sum of proper divisors): 6,288

Factor pairs (a × b = 2,640)

1 × 2640

2 × 1320

3 × 880

4 × 660

5 × 528

6 × 440

8 × 330

10 × 264

11 × 240

12 × 220

15 × 176

16 × 165

20 × 132

22 × 120

24 × 110

30 × 88

33 × 80

40 × 66

44 × 60

48 × 55

First multiples

2,640 · 5,280 (double) · 7,920 · 10,560 · 13,200 · 15,840 · 18,480 · 21,120 · 23,760 · 26,400

Sums & aliquot sequence

As consecutive integers: 879 + 880 + 881 526 + 527 + 528 + 529 + 530 235 + 236 + … + 245 169 + 170 + … + 183

Aliquot sequence: 2,640 → 6,288 → 10,080 → 29,232 → 67,488 → 124,032 → 243,168 → 437,232 → 692,408 → 638,152 → 558,398 → 304,810 → 332,822 → 237,754 → 158,822 → 79,414 → 41,906 — unresolved within range

Continued fraction of √n

√2,640 = [51; (2, 1, 1, 1, 2, 102)]

Period length 6 — the block in parentheses repeats forever.

Representations

In words: two thousand six hundred forty
Ordinal: 2640th
Roman numeral: MMDCXL
Binary: 101001010000
Octal: 5120
Hexadecimal: 0xA50
Base64: ClA=
One's complement: 62,895 (16-bit)
Scientific notation: 2.64 × 10³
As a duration: 2,640 s = 44 minutes

In other bases

ternary (3) 10121210

quaternary (4) 221100

quinary (5) 41030

senary (6) 20120

septenary (7) 10461

nonary (9) 3553

undecimal (11) 1a90

duodecimal (12) 1640

tridecimal (13) 1281

tetradecimal (14) d68

pentadecimal (15) bb0

Palindromic in base 9

As an angle

2,640° = 7 × 360° + 120°

120° ≈ 2.094 rad

Compass bearing: ESE (east-southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹 ·
Egyptian hieroglyphic: 𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆
Greek (Milesian): ͵βχμʹ
Mayan (base 20): 𝋦·𝋬·𝋠
Chinese: 二千六百四十
Chinese (financial): 貳仟陸佰肆拾

In other modern scripts

Eastern Arabic ٢٦٤٠ Devanagari २६४० Bengali ২৬৪০ Tamil ௨௬௪௦ Thai ๒๖๔๐ Tibetan ༢༦༤༠ Khmer ២៦៤០ Lao ໒໖໔໐ Burmese ၂၆၄၀

Digit at this position in famous constants

π — Pi (π): Digit 2,640 = 2
e — Euler's number (e): Digit 2,640 = 3
φ — Golden ratio (φ): Digit 2,640 = 3
√2 — Pythagoras's (√2): Digit 2,640 = 9
ln 2 — Natural log of 2: Digit 2,640 = 5
γ — Euler-Mascheroni (γ): Digit 2,640 = 7

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 2640, here are decompositions:

7 + 2633 = 2640
19 + 2621 = 2640
23 + 2617 = 2640
31 + 2609 = 2640
47 + 2593 = 2640
61 + 2579 = 2640
83 + 2557 = 2640
89 + 2551 = 2640

Showing the first eight; more decompositions exist.

Hex color

#000A50

RGB(0, 10, 80)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.10.80.

Address: 0.0.10.80
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.10.80

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

Musical pitch

Heard as a frequency, 2,640 Hz is closest to:

Concert pitch (A4 = 440 Hz): E7 (2637 Hz, +2¢)
Scientific pitch (C4 = 256 Hz): E7 (2580.3 Hz, +40¢)
Baroque pitch (A4 = 415 Hz): F7 (2635.1 Hz, +3¢)

Position in π

The digit sequence 2640 first appears in π at position 2,076 of the decimal expansion (the 2,076ordinal-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 2640 on Pi Search ↗