Number

228

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

228 (two hundred twenty-eight) is an even 3-digit number. It is a composite number with 12 divisors, and factors as 2² × 3 × 19. Its proper divisors sum to 332, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is CCXXVIII and in binary, 11100100.

Abundant Number Cube-Free Evil Number Harshad / Niven Moran Number Practical Number Recamán's Sequence Refactorable Number Semiperfect Number Year

Interestingness

★ ★ ★ ★ ☆

7 notable facts · grade B

216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240

less more

Historical context — 228 AD

Calendar year

Year 228 (CCXXVIII) 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 — 228 BC

Calendar year

Year 228 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: Tuesday
January 1, 228
Ended on: Wednesday
December 31, 228
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 220s
220–229
Century: 3rd century
201–300
Millennium: 1st millennium
1–1000
Years ago: 1,798
1798 years before 2026.

In other calendars

Hebrew: 3988 / 3989 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Earth zodiac:Monkey
Sexagenary cycle position 45 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 771 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 220 / 221 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 150 / 149 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 12
Digit product: 32
Digital root: 3
Palindrome: No
Bit width: 8 bits
Reversed: 822
Recamán's sequence: a(75) = 228
Square (n²): 51,984
Cube (n³): 11,852,352
Divisor count: 12
σ(n) — sum of divisors: 560
φ(n) — Euler's totient: 72
Sum of prime factors: 26

Primality

Prime factorization: 2 ² × 3 × 19

Nearest primes: 227 (−1) · 229 (+1)

Divisors & multiples

All divisors (12)

1 · 2 · 3 · 4 · 6 · 12 · 19 · 38 · 57 · 76 · 114 (half) · 228

Aliquot sum (sum of proper divisors): 332

Factor pairs (a × b = 228)

1 × 228

2 × 114

3 × 76

4 × 57

6 × 38

12 × 19

First multiples

228 · 456 (double) · 684 · 912 · 1,140 · 1,368 · 1,596 · 1,824 · 2,052 · 2,280

Sums & aliquot sequence

As consecutive integers: 75 + 76 + 77 25 + 26 + … + 32 3 + 4 + … + 21

Aliquot sequence: 228 → 332 → 256 → 255 → 177 → 63 → 41 → 1 → 0 — terminates at zero

Continued fraction of √n

√228 = [15; (10, 30)]

Period length 2 — the block in parentheses repeats forever.

Representations

In words: two hundred twenty-eight
Ordinal: 228th
Roman numeral: CCXXVIII
Binary: 11100100
Octal: 344
Hexadecimal: 0xE4
Base64: 5A==
One's complement: 27 (8-bit)
Scientific notation: 2.28 × 10²
As a duration: 228 s = 3 minutes, 48 seconds

In other bases

ternary (3) 22110

quaternary (4) 3210

quinary (5) 1403

senary (6) 1020

septenary (7) 444

nonary (9) 273

undecimal (11) 198

duodecimal (12) 170

tridecimal (13) 147

tetradecimal (14) 124

pentadecimal (15) 103

Palindromic in base 7

As an angle

228°

228° ≈ 3.979 rad

Compass bearing: SW (southwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): σκηʹ
Mayan (base 20): 𝋫·𝋨
Chinese: 二百二十八
Chinese (financial): 貳佰貳拾捌

In other modern scripts

Eastern Arabic ٢٢٨ Devanagari २२८ Bengali ২২৮ Tamil ௨௨௮ Thai ๒๒๘ Tibetan ༢༢༨ Khmer ២២៨ Lao ໒໒໘ Burmese ၂၂၈

Digit at this position in famous constants

π — Pi (π): Digit 228 = 4
e — Euler's number (e): Digit 228 = 3
φ — Golden ratio (φ): Digit 228 = 3
√2 — Pythagoras's (√2): Digit 228 = 6
ln 2 — Natural log of 2: Digit 228 = 8
γ — Euler-Mascheroni (γ): Digit 228 = 5

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 228, here are decompositions:

5 + 223 = 228
17 + 211 = 228
29 + 199 = 228
31 + 197 = 228
37 + 191 = 228
47 + 181 = 228
61 + 167 = 228
71 + 157 = 228

Showing the first eight; more decompositions exist.

Unicode codepoint

Latin Small Letter A With Diaeresis

U+00E4

Lowercase letter (Ll)

UTF-8 encoding: C3 A4 (2 bytes).

Lookup U+00E4 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#0000E4

RGB(0, 0, 228)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.228.

Address: 0.0.0.228
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.228

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

NANP area code 228

The number 228 is an active NANP area code (North American Numbering Plan).

Primary area: Biloxi / Gulfport
Region: Mississippi
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 228 ↗

Musical pitch

Heard as a frequency, 228 Hz is closest to:

Concert pitch (A4 = 440 Hz): A♯3 (233.1 Hz, -38¢)
Scientific pitch (C4 = 256 Hz): A♯3 (228.1 Hz, -1¢)
Baroque pitch (A4 = 415 Hz): B3 (232.9 Hz, -37¢)