Live analysis

6,440

6,440 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.).

6,440 (six thousand four hundred forty) is an even 4-digit number. It is a composite number with 32 divisors, and factors as 2³ × 5 × 7 × 23. Its proper divisors sum to 10,840, more than the number itself, making it an abundant number. Written other ways, in hexadecimal, 0x1928.

Abundant Number Arithmetic Number Happy Number Harshad / Niven Odious Number Pernicious Number Practical Number Recamán's Sequence Semiperfect Number

Interestingness

★ ★ ★ ★ ☆

6 notable facts · grade B

6,428 6,429 6,430 6,431 6,432 6,433 6,434 6,435 6,436 6,437 6,438 6,439 6,440 6,441 6,442 6,443 6,444 6,445 6,446 6,447 6,448 6,449 6,450 6,451 6,452

less more

Properties

Parity: Even
Digit count: 4
Digit sum: 14
Digit product: 0
Digital root: 5
Palindrome: No
Bit width: 13 bits
Reversed: 446
Recamán's sequence: a(27,020) = 6,440
Square (n²): 41,473,600
Cube (n³): 267,089,984,000
Divisor count: 32
σ(n) — sum of divisors: 17,280
φ(n) — Euler's totient: 2,112
Sum of prime factors: 41

Primality

Prime factorization: 2 ³ × 5 × 7 × 23

Nearest primes: 6,427 (−13) · 6,449 (+9)

Divisors & multiples

All divisors (32)

1 · 2 · 4 · 5 · 7 · 8 · 10 · 14 · 20 · 23 · 28 · 35 · 40 · 46 · 56 · 70 · 92 · 115 · 140 · 161 · 184 · 230 · 280 · 322 · 460 · 644 · 805 · 920 · 1288 · 1610 · 3220 (half) · 6440

Aliquot sum (sum of proper divisors): 10,840

Factor pairs (a × b = 6,440)

1 × 6440

2 × 3220

4 × 1610

5 × 1288

7 × 920

8 × 805

10 × 644

14 × 460

20 × 322

23 × 280

28 × 230

35 × 184

40 × 161

46 × 140

56 × 115

70 × 92

First multiples

6,440 · 12,880 (double) · 19,320 · 25,760 · 32,200 · 38,640 · 45,080 · 51,520 · 57,960 · 64,400

Sums & aliquot sequence

As consecutive integers: 1,286 + 1,287 + 1,288 + 1,289 + 1,290 917 + 918 + … + 923 395 + 396 + … + 410 269 + 270 + … + 291

Aliquot sequence: 6,440 → 10,840 → 13,640 → 20,920 → 26,240 → 38,020 → 41,864 → 36,646 → 19,298 → 9,652 → 8,268 → 12,900 → 25,292 → 18,976 → 18,446 → 10,498 → 5,882 — unresolved within range

Continued fraction of √n

√6,440 = [80; (4, 160)]

Period length 2 — the block in parentheses repeats forever.

Representations

In words: six thousand four hundred forty
Ordinal: 6440th
Binary: 1100100101000
Octal: 14450
Hexadecimal: 0x1928
Base64: GSg=
One's complement: 59,095 (16-bit)
Scientific notation: 6.44 × 10³
As a duration: 6,440 s = 1 hour, 47 minutes, 20 seconds

In other bases

ternary (3) 22211112

quaternary (4) 1210220

quinary (5) 201230

senary (6) 45452

septenary (7) 24530

nonary (9) 8745

undecimal (11) 4925

duodecimal (12) 3888

tridecimal (13) 2c15

tetradecimal (14) 24c0

pentadecimal (15) 1d95

As an angle

6,440° = 17 × 360° + 320°

320° ≈ 5.585 rad

Compass bearing: NW (northwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋
Egyptian hieroglyphic: 𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆
Greek (Milesian): ͵ϛυμʹ
Mayan (base 20): 𝋰·𝋢·𝋠
Chinese: 六千四百四十
Chinese (financial): 陸仟肆佰肆拾

In other modern scripts

Eastern Arabic ٦٤٤٠ Devanagari ६४४० Bengali ৬৪৪০ Tamil ௬௪௪௦ Thai ๖๔๔๐ Tibetan ༦༤༤༠ Khmer ៦៤៤០ Lao ໖໔໔໐ Burmese ၆၄၄၀

Digit at this position in famous constants

π — Pi (π): Digit 6,440 = 0
e — Euler's number (e): Digit 6,440 = 6
φ — Golden ratio (φ): Digit 6,440 = 8
√2 — Pythagoras's (√2): Digit 6,440 = 2
ln 2 — Natural log of 2: Digit 6,440 = 0
γ — Euler-Mascheroni (γ): Digit 6,440 = 0

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 6440, here are decompositions:

13 + 6427 = 6440
19 + 6421 = 6440
43 + 6397 = 6440
61 + 6379 = 6440
67 + 6373 = 6440
73 + 6367 = 6440
79 + 6361 = 6440
97 + 6343 = 6440

Showing the first eight; more decompositions exist.

Unicode codepoint

ᤨ

Limbu Vowel Sign O

U+1928

Non-spacing mark (Mn)

UTF-8 encoding: E1 A4 A8 (3 bytes).

Lookup U+1928 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#001928

RGB(0, 25, 40)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.25.40.

Address: 0.0.25.40
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.25.40

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

Musical pitch

Heard as a frequency, 6,440 Hz is closest to:

Concert pitch (A4 = 440 Hz): G8 (6271.9 Hz, +46¢ — about midway to G♯8)
Scientific pitch (C4 = 256 Hz): G♯8 (6502 Hz, -17¢)
Baroque pitch (A4 = 415 Hz): G♯8 (6267.3 Hz, +47¢ — about midway to A8)

Position in π

The digit sequence 6440 first appears in π at position 17,846 of the decimal expansion (the 17,846ordinal-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 6440 on Pi Search ↗