Number

111

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

111 (one hundred eleven) is an odd 3-digit number. It is a composite number with 4 divisors, and factors as 3 × 37. Its digits read the same forwards and backwards, so it is a palindromic number. Written other ways, in Roman numerals it is CXI and in binary, 1101111.

Arithmetic Number Cube-Free Deficient Number Evil Number Flippable Harshad / Niven Magic Constant Moran Number Nonagonal Palindrome Recamán's Sequence Repdigit Repunit Semiprime Squarefree Strobogrammatic Year Zuckerman Number

Interestingness

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15 notable facts · grade A

99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123

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Historical context — 111 AD

Calendar year

Year 111 (CXI) was a common year starting on Wednesday of the Julian calendar.

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

Historical context — 111 BC

Calendar year

Year 111 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: Common year
Standard 365-day year; not divisible by 4 (or divisible by 100 but not 400).
Days in year: 365
ISO weeks: 53
Long year: contains 53 ISO weeks.
Started on: Thursday
January 1, 111
Ended on: Thursday
December 31, 111
Friday the 13ths: 3
3 Friday the 13ths this year.
Decade: 110s
110–119
Century: 2nd century
101–200
Millennium: 1st millennium
1–1000
Years ago: 1,915
1915 years before 2026.

In other calendars

Hebrew: 3871 / 3872 AM
Rosh Hashanah falls in September/October.
Chinese: Year of the zodiac:Metal zodiac:Pig
Sexagenary cycle position 48 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 654 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Ethiopian: 103 / 104 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 33 / 32 Saka
Indian national calendar; year starts in March.

Properties

Parity: Odd
Digit count: 3
Digit sum: 3
Digit product: 1
Digital root: 3
Palindrome: Yes
Bit width: 7 bits
Recamán's sequence: a(770) = 111
Square (n²): 12,321
Cube (n³): 1,367,631
Divisor count: 4
σ(n) — sum of divisors: 152
φ(n) — Euler's totient: 72
Sum of prime factors: 40

Primality

Prime factorization: 3 × 37

Nearest primes: 109 (−2) · 113 (+2)

Divisors & multiples

All divisors (4)

1 · 3 · 37 · 111

Aliquot sum (sum of proper divisors): 41

Factor pairs (a × b = 111)

1 × 111

3 × 37

First multiples

111 · 222 (double) · 333 · 444 · 555 · 666 · 777 · 888 · 999 · 1,110

Sums & aliquot sequence

As consecutive integers: 55 + 56 36 + 37 + 38 16 + 17 + 18 + 19 + 20 + 21

Aliquot sequence: 111 → 41 → 1 → 0 — terminates at zero

Continued fraction of √n

√111 = [10; (1, 1, 6, 1, 1, 20)]

Period length 6 — the block in parentheses repeats forever.

Representations

In words: one hundred eleven
Ordinal: 111th
Roman numeral: CXI
Binary: 1101111
Octal: 157
Hexadecimal: 0x6F
Base64: bw==
One's complement: 144 (8-bit)
Scientific notation: 1.11 × 10²
As a duration: 111 s = 1 minute, 51 seconds

In other bases

ternary (3) 11010

quaternary (4) 1233

quinary (5) 421

senary (6) 303

septenary (7) 216

nonary (9) 133

undecimal (11) a1

duodecimal (12) 93

tridecimal (13) 87

tetradecimal (14) 7d

pentadecimal (15) 76

Palindromic in base 6

As an angle

111°

111° ≈ 1.937 rad

Compass bearing: ESE (east-southeast)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒁹 𒌋𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic: 𓍢𓎆𓏺
Greek (Milesian): ριαʹ
Mayan (base 20): 𝋥·𝋫
Chinese: 一百一十一
Chinese (financial): 壹佰壹拾壹

In other modern scripts

Eastern Arabic ١١١ Devanagari १११ Bengali ১১১ Tamil ௧௧௧ Thai ๑๑๑ Tibetan ༡༡༡ Khmer ១១១ Lao ໑໑໑ Burmese ၁၁၁

Digit at this position in famous constants

π — Pi (π): Digit 111 = 1
e — Euler's number (e): Digit 111 = 3
φ — Golden ratio (φ): Digit 111 = 7
√2 — Pythagoras's (√2): Digit 111 = 3
ln 2 — Natural log of 2: Digit 111 = 2
γ — Euler-Mascheroni (γ): Digit 111 = 4

Also seen as

ASCII character

As an ASCII codepoint, 111 is o. Printable ASCII character o.

Hex color

#00006F

RGB(0, 0, 111)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.0.111.

Address: 0.0.0.111
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.0.111

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

Musical pitch

Heard as a frequency, 111 Hz is closest to:

Concert pitch (A4 = 440 Hz): A2 (110 Hz, +16¢)
Scientific pitch (C4 = 256 Hz): A♯2 (114 Hz, -47¢ — about midway to A2)
Baroque pitch (A4 = 415 Hz): A♯2 (109.9 Hz, +17¢)

(very low — many laptop and phone speakers can't reproduce it)

As a MIDI note number, 111 is D♯8 (4978 Hz at concert pitch).

Atomic number

On the periodic table, atomic number 111 is Roentgenium (Rg) — period 7.

Roentgenium on Wikipedia ↗