Number

1,145

1,145 is a composite number, odd, a calendar year.

1,145 (one thousand one hundred forty-five) is an odd 4-digit number. It is a composite number with 4 divisors, and factors as 5 × 229. Written other ways, in Roman numerals it is MCXLV and in binary, 10001111001.

Arithmetic Number Cube-Free Deficient Number Evil Number Recamán's Sequence Semiprime Squarefree Year

Interestingness

★ ★ ★ ☆ ☆

5 notable facts · grade C

1,133 1,134 1,135 1,136 1,137 1,138 1,139 1,140 1,141 1,142 1,143 1,144 1,145 1,146 1,147 1,148 1,149 1,150 1,151 1,152 1,153 1,154 1,155 1,156 1,157

less more

Historical context — 1145 AD

Calendar year

Year 1145 (MCXLV) 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 →

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: Monday
January 1, 1145
Ended on: Monday
December 31, 1145
Friday the 13ths: 2
2 Friday the 13ths this year.
Decade: 1140s
1140–1149
Century: 12th century
1101–1200
Millennium: 2nd millennium
1001–2000
Years ago: 881
881 years before 2026.

In other calendars

Hebrew: 4905 / 4906 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 539 / 540 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Wood zodiac:Ox
Sexagenary cycle position 2 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 1688 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 523 / 524 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 1137 / 1138 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 1067 / 1066 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 4
Digit sum: 11
Digit product: 20
Digital root: 2
Palindrome: No
Bit width: 11 bits
Reversed: 5,411
Recamán's sequence: a(1,882) = 1,145
Square (n²): 1,311,025
Cube (n³): 1,501,123,625
Divisor count: 4
σ(n) — sum of divisors: 1,380
φ(n) — Euler's totient: 912
Sum of prime factors: 234

Primality

Prime factorization: 5 × 229

Nearest primes: 1,129 (−16) · 1,151 (+6)

Divisors & multiples

All divisors (4)

1 · 5 · 229 · 1145

Aliquot sum (sum of proper divisors): 235

Factor pairs (a × b = 1,145)

1 × 1145

5 × 229

First multiples

1,145 · 2,290 (double) · 3,435 · 4,580 · 5,725 · 6,870 · 8,015 · 9,160 · 10,305 · 11,450

Sums & aliquot sequence

As a sum of two squares: 11² + 32² = 19² + 28²

As consecutive integers: 572 + 573 227 + 228 + 229 + 230 + 231 110 + 111 + … + 119

Aliquot sequence: 1,145 → 235 → 53 → 1 → 0 — terminates at zero

Continued fraction of √n

√1,145 = [33; (1, 5, 5, 1, 66)]

Period length 5 — the block in parentheses repeats forever.

Representations

In words: one thousand one hundred forty-five
Ordinal: 1145th
Roman numeral: MCXLV
Binary: 10001111001
Octal: 2171
Hexadecimal: 0x479
Base64: BHk=
One's complement: 64,390 (16-bit)
Scientific notation: 1.145 × 10³
As a duration: 1,145 s = 19 minutes, 5 seconds

In other bases

ternary (3) 1120102

quaternary (4) 101321

quinary (5) 14040

senary (6) 5145

septenary (7) 3224

nonary (9) 1512

undecimal (11) 951

duodecimal (12) 7b5

tridecimal (13) 6a1

tetradecimal (14) 5bb

pentadecimal (15) 515

Palindromic in base 15

As an angle

1,145° = 3 × 360° + 65°

65° ≈ 1.134 rad

Compass bearing: ENE (east-northeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒁹𒁹𒁹𒁹𒁹
Egyptian hieroglyphic: 𓆼𓍢𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺
Greek (Milesian): ͵αρμεʹ
Mayan (base 20): 𝋢·𝋱·𝋥
Chinese: 一千一百四十五
Chinese (financial): 壹仟壹佰肆拾伍

In other modern scripts

Eastern Arabic ١١٤٥ Devanagari ११४५ Bengali ১১৪৫ Tamil ௧௧௪௫ Thai ๑๑๔๕ Tibetan ༡༡༤༥ Khmer ១១៤៥ Lao ໑໑໔໕ Burmese ၁၁၄၅

Digit at this position in famous constants

π — Pi (π): Digit 1,145 = 0
e — Euler's number (e): Digit 1,145 = 1
φ — Golden ratio (φ): Digit 1,145 = 5
√2 — Pythagoras's (√2): Digit 1,145 = 8
ln 2 — Natural log of 2: Digit 1,145 = 7
γ — Euler-Mascheroni (γ): Digit 1,145 = 2

Also seen as

Unicode codepoint

Cyrillic Small Letter Uk

U+0479

Lowercase letter (Ll)

UTF-8 encoding: D1 B9 (2 bytes).

Lookup U+0479 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000479

RGB(0, 4, 121)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.4.121.

Address: 0.0.4.121
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.4.121

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

Musical pitch

Heard as a frequency, 1,145 Hz is closest to:

Concert pitch (A4 = 440 Hz): D6 (1174.7 Hz, -44¢)
Scientific pitch (C4 = 256 Hz): D6 (1149.4 Hz, -7¢)
Baroque pitch (A4 = 415 Hz): D♯6 (1173.8 Hz, -43¢)

Position in π

The digit sequence 1145 first appears in π at position 20,913 of the decimal expansion (the 20,913ordinal-suffix:th digit after the integer 3).

Search range: the first 1,000,000 fractional digits of π. Any 6-digit-or-shorter string is virtually guaranteed to appear in there — the more interesting signal is the position.

Look up 1145 on Pi Search ↗