Number

428

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

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

Historical context — 428 AD

Calendar year

Year 428 (CDXXVIII) was a leap year starting on Sunday of the Julian calendar.

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Historical context — 428 BC

Calendar year

Year 428 BC was a year of the pre-Julian Roman calendar.

Excerpt from Wikipedia (en) ↗ · Licensed CC BY-SA 4.0 · English fallback 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: Saturday
January 1, 428
Ended on: Sunday
December 31, 428
Friday the 13ths: 1
One Friday the 13th this year.
Decade: 420s
420–429
Century: 5th century
401–500
Millennium: 1st millennium
1–1000
Years ago: 1,598
1598 years before 2026.

In other calendars

Hebrew: 4188 / 4189 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Earth zodiac:Dragon
Sexagenary cycle position 5 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 971 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 420 / 421 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 350 / 349 Saka
Indian national calendar; year starts in March.

Properties

Parity: Even
Digit count: 3
Digit sum: 14
Digit product: 64
Digital root: 5
Palindrome: No
Bit width: 9 bits
Reversed: 824
Recamán's sequence: a(4,787) = 428
Square (n²): 183,184
Cube (n³): 78,402,752
Divisor count: 6
σ(n) — sum of divisors: 756
φ(n) — Euler's totient: 212
Sum of prime factors: 111

Primality

Prime factorization: 2 ² × 107

Nearest primes: 421 (−7) · 431 (+3)

Divisors & multiples

All divisors (6)

1 · 2 · 4 · 107 · 214 (half) · 428

Aliquot sum (sum of proper divisors): 328

Factor pairs (a × b = 428)

1 × 428

2 × 214

4 × 107

First multiples

428 · 856 (double) · 1,284 · 1,712 · 2,140 · 2,568 · 2,996 · 3,424 · 3,852 · 4,280

Sums & aliquot sequence

As consecutive integers: 50 + 51 + … + 57

Aliquot sequence: 428 → 328 → 302 → 154 → 134 → 70 → 74 → 40 → 50 → 43 → 1 → 0 — terminates at zero

Representations

In words: four hundred twenty-eight
Ordinal: 428th
Roman numeral: CDXXVIII
Binary: 110101100
Octal: 654
Hexadecimal: 0x1AC
Base64: Aaw=
One's complement: 65,107 (16-bit)

In other bases

ternary (3) 120212

quaternary (4) 12230

quinary (5) 3203

senary (6) 1552

septenary (7) 1151

nonary (9) 525

undecimal (11) 35a

duodecimal (12) 2b8

tridecimal (13) 26c

tetradecimal (14) 228

pentadecimal (15) 1d8

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓍢𓍢𓍢𓍢𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): υκηʹ
Mayan (base 20): 𝋡·𝋡·𝋨
Chinese: 四百二十八
Chinese (financial): 肆佰貳拾捌

In other modern scripts

Eastern Arabic ٤٢٨ Devanagari ४२८ Bengali ৪২৮ Tamil ௪௨௮ Thai ๔๒๘ Tibetan ༤༢༨ Khmer ៤២៨ Lao ໔໒໘ Burmese ၄၂၈

Digit at this position in famous constants

π — Pi (π): Digit 428 = 1
e — Euler's number (e): Digit 428 = 1
φ — Golden ratio (φ): Digit 428 = 2
√2 — Pythagoras's (√2): Digit 428 = 0
ln 2 — Natural log of 2: Digit 428 = 4
γ — Euler-Mascheroni (γ): Digit 428 = 5

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 428, here are decompositions:

7 + 421 = 428
19 + 409 = 428
31 + 397 = 428
61 + 367 = 428
79 + 349 = 428
97 + 331 = 428
151 + 277 = 428
157 + 271 = 428

Showing the first eight; more decompositions exist.

Unicode codepoint

Latin Capital Letter T With Hook

U+01AC

Uppercase letter (Lu)

UTF-8 encoding: C6 AC (2 bytes).

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

Hex color

#0001AC

RGB(0, 1, 172)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.1.172.

Address: 0.0.1.172
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.1.172

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