440
440 is a composite number, even, a calendar year.
440 (four hundred forty) is an even 3-digit number. It is a composite number with 16 divisors, and factors as 2³ × 5 × 11. Its proper divisors sum to 640, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is CDXL and in binary, 110111000.
Interestingness
Historical context — 440 AD
Calendar year
Year 440 (CDXL) was a leap year starting on Monday of the Julian calendar.
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Historical context — 440 BC
Calendar year
Year 440 BC was a year of the pre-Julian Roman calendar.
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Year facts
- Year type
-
Leap year
Divisible by 4 and not by 100; February has 29 days.
- Days in year
- 366
- ISO weeks
- 52
- Started on
-
Sunday
January 1, 440
- Ended on
-
Monday
December 31, 440
- Friday the 13ths
-
3
3 Friday the 13ths this year.
- Decade
-
440s
440–449
- Century
-
5th century
401–500
- Millennium
-
1st millennium
1–1000
- Years ago
-
1,586
1586 years before 2026.
In other calendars
- Hebrew
-
4200 / 4201 AM
Rosh Hashanah falls in September/October.
- Chinese
-
Year of the zodiac:Metal zodiac:Dragon
Sexagenary cycle position 17 of 60. Lunar new year falls in late January / mid-February.
- Buddhist Era
-
983 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
- Ethiopian
-
432 / 433 ET
Year boundary at Enkutatash (September 11/12).
- Indian National (Saka)
-
362 / 361 Saka
Indian national calendar; year starts in March.
Properties
Primality
Prime factorization: 2 3 × 5 × 11
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√440 = [20; (1, 40)]
Period length 2 — the block in parentheses repeats forever.
Representations
- In words
- four hundred forty
- Ordinal
- 440th
- Roman numeral
- CDXL
- Binary
- 110111000
- Octal
- 670
- Hexadecimal
- 0x1B8
- Base64
- Abg=
- One's complement
- 65,095 (16-bit)
- Scientific notation
- 4.4 × 10²
- As a duration
- 440 s = 7 minutes, 20 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋
- Egyptian hieroglyphic
- 𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆
- Greek (Milesian)
- υμʹ
- Mayan (base 20)
- 𝋡·𝋢·𝋠
- Chinese
- 四百四十
- Chinese (financial)
- 肆佰肆拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 440 = 7
- e — Euler's number (e)
- Digit 440 = 4
- φ — Golden ratio (φ)
- Digit 440 = 7
- √2 — Pythagoras's (√2)
- Digit 440 = 2
- ln 2 — Natural log of 2
- Digit 440 = 6
- γ — Euler-Mascheroni (γ)
- Digit 440 = 9
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 440, here are decompositions:
- 7 + 433 = 440
- 19 + 421 = 440
- 31 + 409 = 440
- 43 + 397 = 440
- 61 + 379 = 440
- 67 + 373 = 440
- 73 + 367 = 440
- 103 + 337 = 440
Showing the first eight; more decompositions exist.
UTF-8 encoding: C6 B8 (2 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.184.
- Address
- 0.0.1.184
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.1.184
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The number 440 is an active NANP area code (North American Numbering Plan).
- Primary area
- Eastern / Western suburbs of Cleveland
- Region
- Ohio
- Country
- United States
Most NANP area codes have multiple overlays in dense regions; the primary area listed is the historic/largest population center for this code.
Heard as a frequency, 440 Hz is closest to:
- Concert pitch (A4 = 440 Hz): A4 (440 Hz, exact)
- Scientific pitch (C4 = 256 Hz): A4 (430.5 Hz, +38¢)
- Baroque pitch (A4 = 415 Hz): A♯4 (439.7 Hz, +1¢)
Concert pitch — the modern standard tuning reference (the A above middle C), fixed by ISO 16.
On an ingredients label, E440 is Pectin, a thickener, stabiliser or emulsifier — what sets jam.
Related reading
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.