Number

309

309 is a composite number, odd, a calendar year.

Arithmetic Number Deficient Number Odious Number Pernicious Number Recamán's Sequence Semiprime Squarefree Year

Historical context — 309 AD

Calendar year

Year 309 (CCCIX) was a common year starting on Saturday of the Julian calendar.

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Historical context — 309 BC

Calendar year

Year 309 BC was a year of the pre-Julian Roman calendar.

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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: Friday
January 1, 309
Ended on: Friday
December 31, 309
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 300s
300–309
Century: 4th century
301–400
Millennium: 1st millennium
1–1000
Years ago: 1,717
1717 years before 2026.

In other calendars

Hebrew: 4069 / 4070 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Earth zodiac:Snake
Sexagenary cycle position 6 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 852 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 301 / 302 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 231 / 230 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 3
Digit sum: 12
Digit product: 0
Digital root: 3
Palindrome: No
Bit width: 9 bits
Reversed: 903
Recamán's sequence: a(630) = 309
Square (n²): 95,481
Cube (n³): 29,503,629
Divisor count: 4
σ(n) — sum of divisors: 416
φ(n) — Euler's totient: 204
Sum of prime factors: 106

Primality

Prime factorization: 3 × 103

Nearest primes: 307 (−2) · 311 (+2)

Divisors & multiples

All divisors (4)

1 · 3 · 103 · 309

Aliquot sum (sum of proper divisors): 107

Factor pairs (a × b = 309)

1 × 309

3 × 103

First multiples

309 · 618 (double) · 927 · 1,236 · 1,545 · 1,854 · 2,163 · 2,472 · 2,781 · 3,090

Sums & aliquot sequence

As consecutive integers: 154 + 155 102 + 103 + 104 49 + 50 + 51 + 52 + 53 + 54

Aliquot sequence: 309 → 107 → 1 → 0 — terminates at zero

Representations

In words: three hundred nine
Ordinal: 309th
Roman numeral: CCCIX
Binary: 100110101
Octal: 465
Hexadecimal: 0x135
Base64: ATU=
One's complement: 65,226 (16-bit)

In other bases

ternary (3) 102110

quaternary (4) 10311

quinary (5) 2214

senary (6) 1233

septenary (7) 621

nonary (9) 373

undecimal (11) 261

duodecimal (12) 219

tridecimal (13) 1aa

tetradecimal (14) 181

pentadecimal (15) 159

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓍢𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): τθʹ
Mayan (base 20): 𝋯·𝋩
Chinese: 三百零九
Chinese (financial): 參佰零玖

In other modern scripts

Eastern Arabic ٣٠٩ Devanagari ३०९ Bengali ৩০৯ Tamil ௩௦௯ Thai ๓๐๙ Tibetan ༣༠༩ Khmer ៣០៩ Lao ໓໐໙ Burmese ၃၀၉

Digit at this position in famous constants

π — Pi (π): Digit 309 = 0
e — Euler's number (e): Digit 309 = 6
φ — Golden ratio (φ): Digit 309 = 4
√2 — Pythagoras's (√2): Digit 309 = 9
ln 2 — Natural log of 2: Digit 309 = 0
γ — Euler-Mascheroni (γ): Digit 309 = 3

Also seen as

Unicode codepoint

Latin Small Letter J With Circumflex

U+0135

Lowercase letter (Ll)

UTF-8 encoding: C4 B5 (2 bytes).

Lookup U+0135 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000135

RGB(0, 1, 53)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.53.

Address: 0.0.1.53
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.1.53

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

NANP area code 309

The number 309 is an active NANP area code (North American Numbering Plan).

Primary area: Peoria / Bloomington
Region: Illinois
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.

Look up area code 309 ↗