Number

490

490 is a composite number, even, a calendar year.

490 (four hundred ninety) is an even 3-digit number. It is a composite number with 12 divisors, and factors as 2 × 5 × 7². Its proper divisors sum to 536, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is CDXC and in binary, 111101010.

Abundant Number Cube-Free Evil Number Happy Number Partition Number Recamán's Sequence Self Number Semiperfect Number Year

Interestingness

★ ★ ★ ★ ☆

6 notable facts · grade B

478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502

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Historical context — 490 AD

Calendar year

Year 490 (CDXC) was a common year starting on Monday of the Julian calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 Read the full article on Wikipedia →

Notable events — 490 BC

Sep 12 The Athenians defeat the Persians at the Battle of Marathon.

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

Year facts

Year type: Common year
Standard 365-day year; not divisible by 4 (or divisible by 100 but not 400).
Days in year: 365
ISO weeks: 52
Started on: Sunday
January 1, 490
Ended on: Sunday
December 31, 490
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 490s
490–499
Century: 5th century
401–500
Millennium: 1st millennium
1–1000
Years ago: 1,536
1536 years before 2026.

In other calendars

Hebrew: 4250 / 4251 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Metal zodiac:Horse
Sexagenary cycle position 7 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 1033 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 482 / 483 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 412 / 411 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 13
Digit product: 0
Digital root: 4
Palindrome: No
Bit width: 9 bits
Reversed: 94
Recamán's sequence: a(232) = 490
Square (n²): 240,100
Cube (n³): 117,649,000
Divisor count: 12
σ(n) — sum of divisors: 1,026
φ(n) — Euler's totient: 168
Sum of prime factors: 21

Primality

Prime factorization: 2 × 5 × 7 ²

Nearest primes: 487 (−3) · 491 (+1)

Divisors & multiples

All divisors (12)

1 · 2 · 5 · 7 · 10 · 14 · 35 · 49 · 70 · 98 · 245 (half) · 490

Aliquot sum (sum of proper divisors): 536

Factor pairs (a × b = 490)

1 × 490

2 × 245

5 × 98

7 × 70

10 × 49

14 × 35

First multiples

490 · 980 (double) · 1,470 · 1,960 · 2,450 · 2,940 · 3,430 · 3,920 · 4,410 · 4,900

Sums & aliquot sequence

As a sum of two squares: 7² + 21²

As consecutive integers: 121 + 122 + 123 + 124 96 + 97 + 98 + 99 + 100 67 + 68 + … + 73 15 + 16 + … + 34

Aliquot sequence: 490 → 536 → 484 → 447 → 153 → 81 → 40 → 50 → 43 → 1 → 0 — terminates at zero

Continued fraction of √n

√490 = [22; (7, 2, 1, 4, 4, 4, 1, 2, 7, 44)]

Period length 10 — the block in parentheses repeats forever.

Representations

In words: four hundred ninety
Ordinal: 490th
Roman numeral: CDXC
Binary: 111101010
Octal: 752
Hexadecimal: 0x1EA
Base64: Aeo=
One's complement: 65,045 (16-bit)
Scientific notation: 4.9 × 10²
As a duration: 490 s = 8 minutes, 10 seconds

In other bases

ternary (3) 200011

quaternary (4) 13222

quinary (5) 3430

senary (6) 2134

septenary (7) 1300

nonary (9) 604

undecimal (11) 406

duodecimal (12) 34a

tridecimal (13) 2b9

tetradecimal (14) 270

pentadecimal (15) 22a

As an angle

490° = 1 × 360° + 130°

130° ≈ 2.269 rad

Compass bearing: SE (southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋
Egyptian hieroglyphic: 𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆
Greek (Milesian): υϟʹ
Mayan (base 20): 𝋡·𝋤·𝋪
Chinese: 四百九十
Chinese (financial): 肆佰玖拾

In other modern scripts

Eastern Arabic ٤٩٠ Devanagari ४९० Bengali ৪৯০ Tamil ௪௯௦ Thai ๔๙๐ Tibetan ༤༩༠ Khmer ៤៩០ Lao ໔໙໐ Burmese ၄၉၀

Digit at this position in famous constants

π — Pi (π): Digit 490 = 8
e — Euler's number (e): Digit 490 = 9
φ — Golden ratio (φ): Digit 490 = 0
√2 — Pythagoras's (√2): Digit 490 = 8
ln 2 — Natural log of 2: Digit 490 = 4
γ — Euler-Mascheroni (γ): Digit 490 = 6

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 490, here are decompositions:

3 + 487 = 490
11 + 479 = 490
23 + 467 = 490
29 + 461 = 490
41 + 449 = 490
47 + 443 = 490
59 + 431 = 490
71 + 419 = 490

Showing the first eight; more decompositions exist.

Unicode codepoint

Latin Capital Letter O With Ogonek

U+01EA

Uppercase letter (Lu)

UTF-8 encoding: C7 AA (2 bytes).

Lookup U+01EA on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#0001EA

RGB(0, 1, 234)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.234.

Address: 0.0.1.234
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.1.234

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

Musical pitch

Heard as a frequency, 490 Hz is closest to:

Concert pitch (A4 = 440 Hz): B4 (493.9 Hz, -14¢)
Scientific pitch (C4 = 256 Hz): B4 (483.3 Hz, +24¢)
Baroque pitch (A4 = 415 Hz): C5 (493.5 Hz, -12¢)