Number

312

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

312 (three hundred twelve) is an even 3-digit number. It is a composite number with 16 divisors, and factors as 2³ × 3 × 13. Its proper divisors sum to 528, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is CCCXII and in binary, 100111000.

Abundant Number Evil Number Harshad / Niven Practical Number Recamán's Sequence Self Number Semiperfect Number Year Zuckerman Number

Interestingness

★ ★ ★ ★ ☆

6 notable facts · grade B

300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324

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Historical context — 312 AD

Calendar year

Year 312 (CCCXII) was a leap year starting on Tuesday of the Julian calendar.

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

Historical context — 312 BC

Calendar year

Year 312 BC was a year of the pre-Julian Roman calendar.

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

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: Monday
January 1, 312
Ended on: Tuesday
December 31, 312
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 310s
310–319
Century: 4th century
301–400
Millennium: 1st millennium
1–1000
Years ago: 1,714
1714 years before 2026.

In other calendars

Hebrew: 4072 / 4073 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Water zodiac:Monkey
Sexagenary cycle position 9 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 855 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 304 / 305 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 234 / 233 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 6
Digit product: 6
Digital root: 6
Palindrome: No
Bit width: 9 bits
Reversed: 213
Recamán's sequence: a(624) = 312
Square (n²): 97,344
Cube (n³): 30,371,328
Divisor count: 16
σ(n) — sum of divisors: 840
φ(n) — Euler's totient: 96
Sum of prime factors: 22

Primality

Prime factorization: 2 ³ × 3 × 13

Nearest primes: 311 (−1) · 313 (+1)

Divisors & multiples

All divisors (16)

1 · 2 · 3 · 4 · 6 · 8 · 12 · 13 · 24 · 26 · 39 · 52 · 78 · 104 · 156 (half) · 312

Aliquot sum (sum of proper divisors): 528

Factor pairs (a × b = 312)

1 × 312

2 × 156

3 × 104

4 × 78

6 × 52

8 × 39

12 × 26

13 × 24

First multiples

312 · 624 (double) · 936 · 1,248 · 1,560 · 1,872 · 2,184 · 2,496 · 2,808 · 3,120

Sums & aliquot sequence

As consecutive integers: 103 + 104 + 105 18 + 19 + … + 30 12 + 13 + … + 27

Aliquot sequence: 312 → 528 → 960 → 2,088 → 3,762 → 5,598 → 6,570 → 10,746 → 13,254 → 13,830 → 19,434 → 20,886 → 21,606 → 25,098 → 26,742 → 26,754 → 40,446 — unresolved within range

Continued fraction of √n

√312 = [17; (1, 1, 1, 34)]

Period length 4 — the block in parentheses repeats forever.

Representations

In words: three hundred twelve
Ordinal: 312th
Roman numeral: CCCXII
Binary: 100111000
Octal: 470
Hexadecimal: 0x138
Base64: ATg=
One's complement: 65,223 (16-bit)
Scientific notation: 3.12 × 10²
As a duration: 312 s = 5 minutes, 12 seconds

In other bases

ternary (3) 102120

quaternary (4) 10320

quinary (5) 2222

senary (6) 1240

septenary (7) 624

nonary (9) 376

undecimal (11) 264

duodecimal (12) 220

tridecimal (13) 1b0

tetradecimal (14) 184

pentadecimal (15) 15c

Palindromic in base 5

As an angle

312°

312° ≈ 5.445 rad

Compass bearing: NW (northwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹𒁹 𒌋𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓍢𓎆𓏺𓏺
Greek (Milesian): τιβʹ
Mayan (base 20): 𝋯·𝋬
Chinese: 三百一十二
Chinese (financial): 參佰壹拾貳

In other modern scripts

Eastern Arabic ٣١٢ Devanagari ३१२ Bengali ৩১২ Tamil ௩௧௨ Thai ๓๑๒ Tibetan ༣༡༢ Khmer ៣១២ Lao ໓໑໒ Burmese ၃၁၂

Digit at this position in famous constants

π — Pi (π): Digit 312 = 0
e — Euler's number (e): Digit 312 = 3
φ — Golden ratio (φ): Digit 312 = 4
√2 — Pythagoras's (√2): Digit 312 = 4
ln 2 — Natural log of 2: Digit 312 = 0
γ — Euler-Mascheroni (γ): Digit 312 = 6

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 312, here are decompositions:

5 + 307 = 312
19 + 293 = 312
29 + 283 = 312
31 + 281 = 312
41 + 271 = 312
43 + 269 = 312
61 + 251 = 312
71 + 241 = 312

Showing the first eight; more decompositions exist.

Unicode codepoint

Latin Small Letter Kra

U+0138

Lowercase letter (Ll)

UTF-8 encoding: C4 B8 (2 bytes).

Lookup U+0138 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000138

RGB(0, 1, 56)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.56.

Address: 0.0.1.56
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.1.56

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

NANP area code 312

The number 312 is an active NANP area code (North American Numbering Plan).

Primary area: Downtown Chicago
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 312 ↗

Musical pitch

Heard as a frequency, 312 Hz is closest to:

Concert pitch (A4 = 440 Hz): D♯4 (311.1 Hz, +5¢)
Scientific pitch (C4 = 256 Hz): D♯4 (304.4 Hz, +42¢)
Baroque pitch (A4 = 415 Hz): E4 (310.9 Hz, +6¢)