Number

1,440

1,440 is a composite number, even, a calendar year.

1,440 (one thousand four hundred forty) is an even 4-digit number. It is a composite number with 36 divisors, and factors as 2⁵ × 3² × 5. Its proper divisors sum to 3,474, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is MCDXL and in binary, 10110100000.

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

Interestingness

★ ★ ★ ★ ☆

7 notable facts · grade B

1,428 1,429 1,430 1,431 1,432 1,433 1,434 1,435 1,436 1,437 1,438 1,439 1,440 1,441 1,442 1,443 1,444 1,445 1,446 1,447 1,448 1,449 1,450 1,451 1,452

less more

Notable events — 1440 AD

Undated Johannes Gutenberg begins developing his movable-type printing press.

Events compiled from Wikipedia ↗ · Licensed CC BY-SA 4.0

Year facts

Year type: Leap year
Divisible by 4 and not by 100; February has 29 days.
Days in year: 366
ISO weeks: 53
Long year: contains 53 ISO weeks.
Started on: Wednesday
January 1, 1440
Ended on: Thursday
December 31, 1440
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 1440s
1440–1449
Century: 15th century
1401–1500
Millennium: 2nd millennium
1001–2000
Years ago: 586
586 years before 2026.

In other calendars

Hebrew: 5200 / 5201 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 843 / 844 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Metal zodiac:Monkey
Sexagenary cycle position 57 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 1983 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 818 / 819 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 1432 / 1433 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 1362 / 1361 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 4
Digit sum: 9
Digit product: 0
Digital root: 9
Palindrome: No
Bit width: 11 bits
Reversed: 441
Recamán's sequence: a(1,680) = 1,440
Square (n²): 2,073,600
Cube (n³): 2,985,984,000
Divisor count: 36
σ(n) — sum of divisors: 4,914
φ(n) — Euler's totient: 384
Sum of prime factors: 21

Primality

Prime factorization: 2 ⁵ × 3 ² × 5

Nearest primes: 1,439 (−1) · 1,447 (+7)

Divisors & multiples

All divisors (36)

1 · 2 · 3 · 4 · 5 · 6 · 8 · 9 · 10 · 12 · 15 · 16 · 18 · 20 · 24 · 30 · 32 · 36 · 40 · 45 · 48 · 60 · 72 · 80 · 90 · 96 · 120 · 144 · 160 · 180 · 240 · 288 · 360 · 480 · 720 (half) · 1440

Aliquot sum (sum of proper divisors): 3,474

Factor pairs (a × b = 1,440)

1 × 1440

2 × 720

3 × 480

4 × 360

5 × 288

6 × 240

8 × 180

9 × 160

10 × 144

12 × 120

15 × 96

16 × 90

18 × 80

20 × 72

24 × 60

30 × 48

32 × 45

36 × 40

First multiples

1,440 · 2,880 (double) · 4,320 · 5,760 · 7,200 · 8,640 · 10,080 · 11,520 · 12,960 · 14,400

Sums & aliquot sequence

As a sum of two squares: 12² + 36²

As consecutive integers: 479 + 480 + 481 286 + 287 + 288 + 289 + 290 156 + 157 + … + 164 89 + 90 + … + 103

Aliquot sequence: 1,440 → 3,474 → 4,092 → 6,660 → 14,088 → 21,192 → 31,848 → 47,832 → 71,808 → 148,512 → 359,520 → 946,848 → 1,895,712 → 4,539,360 → 12,180,336 → 23,781,648 → 44,267,568 — unresolved within range

Continued fraction of √n

√1,440 = [37; (1, 17, 1, 74)]

Period length 4 — the block in parentheses repeats forever.

Representations

In words: one thousand four hundred forty
Ordinal: 1440th
Roman numeral: MCDXL
Binary: 10110100000
Octal: 2640
Hexadecimal: 0x5A0
Base64: BaA=
One's complement: 64,095 (16-bit)
Scientific notation: 1.44 × 10³
As a duration: 1,440 s = 24 minutes

In other bases

ternary (3) 1222100

quaternary (4) 112200

quinary (5) 21230

senary (6) 10400

septenary (7) 4125

nonary (9) 1870

undecimal (11) 109a

duodecimal (12) a00

tridecimal (13) 86a

tetradecimal (14) 74c

pentadecimal (15) 660

As an angle

1,440° = 4 × 360°

0° ≈ 0 rad

Compass bearing: N (north)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒁹𒁹𒁹𒁹 ·
Egyptian hieroglyphic: 𓆼𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆
Greek (Milesian): ͵αυμʹ
Mayan (base 20): 𝋣·𝋬·𝋠
Chinese: 一千四百四十
Chinese (financial): 壹仟肆佰肆拾

In other modern scripts

Eastern Arabic ١٤٤٠ Devanagari १४४० Bengali ১৪৪০ Tamil ௧௪௪௦ Thai ๑๔๔๐ Tibetan ༡༤༤༠ Khmer ១៤៤០ Lao ໑໔໔໐ Burmese ၁၄၄၀

Digit at this position in famous constants

π — Pi (π): Digit 1,440 = 3
e — Euler's number (e): Digit 1,440 = 5
φ — Golden ratio (φ): Digit 1,440 = 9
√2 — Pythagoras's (√2): Digit 1,440 = 6
ln 2 — Natural log of 2: Digit 1,440 = 6
γ — Euler-Mascheroni (γ): Digit 1,440 = 5

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1440, here are decompositions:

7 + 1433 = 1440
11 + 1429 = 1440
13 + 1427 = 1440
17 + 1423 = 1440
31 + 1409 = 1440
41 + 1399 = 1440
59 + 1381 = 1440
67 + 1373 = 1440

Showing the first eight; more decompositions exist.

Unicode codepoint

Hebrew Accent Telisha Gedola

U+05A0

Non-spacing mark (Mn)

UTF-8 encoding: D6 A0 (2 bytes).

Lookup U+05A0 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#0005A0

RGB(0, 5, 160)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.5.160.

Address: 0.0.5.160
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.5.160

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

Musical pitch

Heard as a frequency, 1,440 Hz is closest to:

Concert pitch (A4 = 440 Hz): F♯6 (1480 Hz, -47¢ — about midway to F6)
Scientific pitch (C4 = 256 Hz): F♯6 (1448.2 Hz, -10¢)
Baroque pitch (A4 = 415 Hz): G6 (1478.9 Hz, -46¢ — about midway to F♯6)

Time & calendar

1,440 is the number of minutes in a day (24 × 60).

Units of time — Wikipedia ↗

Position in π

The digit sequence 1440 first appears in π at position 23,902 of the decimal expansion (the 23,902ordinal-suffix:nd 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 1440 on Pi Search ↗