Number

1,580

1,580 is a composite number, even, a calendar year.

1,580 (one thousand five hundred eighty) is an even 4-digit number. It is a composite number with 12 divisors, and factors as 2² × 5 × 79. Its proper divisors sum to 1,780, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is MDLXXX and in binary, 11000101100.

Abundant Number Arithmetic Number Cube-Free Gapful Number Odious Number Pernicious Number Recamán's Sequence Semiperfect Number Year

Interestingness

★ ★ ★ ☆ ☆

5 notable facts · grade C

1,568 1,569 1,570 1,571 1,572 1,573 1,574 1,575 1,576 1,577 1,578 1,579 1,580 1,581 1,582 1,583 1,584 1,585 1,586 1,587 1,588 1,589 1,590 1,591 1,592

less more

Notable events — 1580 AD

Sep 26 Francis Drake completes his circumnavigation.
Aug 25 Spain seizes Portugal in a personal union under Philip II.
Undated Michel de Montaigne publishes his Essais.

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: 52
Started on: Tuesday
January 1, 1580
Ended on: Wednesday
December 31, 1580
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 1580s
1580–1589
Century: 16th century
1501–1600
Millennium: 2nd millennium
1001–2000
Years ago: 446
446 years before 2026.

In other calendars

Hebrew: 5340 / 5341 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 987 / 988 AH
Lunar calendar; year spans differ from Gregorian.
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: 2123 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 958 / 959 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 1572 / 1573 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 1502 / 1501 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 4
Digit sum: 14
Digit product: 0
Digital root: 5
Palindrome: No
Bit width: 11 bits
Reversed: 851
Recamán's sequence: a(1,388) = 1,580
Square (n²): 2,496,400
Cube (n³): 3,944,312,000
Divisor count: 12
σ(n) — sum of divisors: 3,360
φ(n) — Euler's totient: 624
Sum of prime factors: 88

Primality

Prime factorization: 2 ² × 5 × 79

Nearest primes: 1,579 (−1) · 1,583 (+3)

Divisors & multiples

All divisors (12)

1 · 2 · 4 · 5 · 10 · 20 · 79 · 158 · 316 · 395 · 790 (half) · 1580

Aliquot sum (sum of proper divisors): 1,780

Factor pairs (a × b = 1,580)

1 × 1580

2 × 790

4 × 395

5 × 316

10 × 158

20 × 79

First multiples

1,580 · 3,160 (double) · 4,740 · 6,320 · 7,900 · 9,480 · 11,060 · 12,640 · 14,220 · 15,800

Sums & aliquot sequence

As consecutive integers: 314 + 315 + 316 + 317 + 318 194 + 195 + … + 201 20 + 21 + … + 59

Aliquot sequence: 1,580 → 1,780 → 2,000 → 2,836 → 2,134 → 1,394 → 874 → 566 → 286 → 218 → 112 → 136 → 134 → 70 → 74 → 40 → 50 — unresolved within range

Continued fraction of √n

√1,580 = [39; (1, 2, 1, 78)]

Period length 4 — the block in parentheses repeats forever.

Representations

In words: one thousand five hundred eighty
Ordinal: 1580th
Roman numeral: MDLXXX
Binary: 11000101100
Octal: 3054
Hexadecimal: 0x62C
Base64: Biw=
One's complement: 63,955 (16-bit)
Scientific notation: 1.58 × 10³
As a duration: 1,580 s = 26 minutes, 20 seconds

In other bases

ternary (3) 2011112

quaternary (4) 120230

quinary (5) 22310

senary (6) 11152

septenary (7) 4415

nonary (9) 2145

undecimal (11) 1207

duodecimal (12) ab8

tridecimal (13) 947

tetradecimal (14) 80c

pentadecimal (15) 705

As an angle

1,580° = 4 × 360° + 140°

140° ≈ 2.443 rad

Compass bearing: SE (southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋
Egyptian hieroglyphic: 𓆼𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆
Greek (Milesian): ͵αφπʹ
Mayan (base 20): 𝋣·𝋳·𝋠
Chinese: 一千五百八十
Chinese (financial): 壹仟伍佰捌拾

In other modern scripts

Eastern Arabic ١٥٨٠ Devanagari १५८० Bengali ১৫৮০ Tamil ௧௫௮௦ Thai ๑๕๘๐ Tibetan ༡༥༨༠ Khmer ១៥៨០ Lao ໑໕໘໐ Burmese ၁၅၈၀

Digit at this position in famous constants

π — Pi (π): Digit 1,580 = 5
e — Euler's number (e): Digit 1,580 = 3
φ — Golden ratio (φ): Digit 1,580 = 1
√2 — Pythagoras's (√2): Digit 1,580 = 9
ln 2 — Natural log of 2: Digit 1,580 = 3
γ — Euler-Mascheroni (γ): Digit 1,580 = 4

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 1580, here are decompositions:

13 + 1567 = 1580
31 + 1549 = 1580
37 + 1543 = 1580
97 + 1483 = 1580
109 + 1471 = 1580
127 + 1453 = 1580
151 + 1429 = 1580
157 + 1423 = 1580

Showing the first eight; more decompositions exist.

Unicode codepoint

Arabic Letter Jeem

U+062C

Other letter (Lo)

UTF-8 encoding: D8 AC (2 bytes).

Lookup U+062C on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00062C

RGB(0, 6, 44)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.6.44.

Address: 0.0.6.44
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.6.44

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

Musical pitch

Heard as a frequency, 1,580 Hz is closest to:

Concert pitch (A4 = 440 Hz): G6 (1568 Hz, +13¢)
Scientific pitch (C4 = 256 Hz): G♯6 (1625.5 Hz, -49¢ — about midway to G6)
Baroque pitch (A4 = 415 Hz): G♯6 (1566.8 Hz, +14¢)

Position in π

The digit sequence 1580 first appears in π at position 18,225 of the decimal expansion (the 18,225ordinal-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 1580 on Pi Search ↗