Number

2,100

2,100 is a composite number, even, a calendar year.

2,100 (two thousand one hundred) is an even 4-digit number. It is a composite number with 36 divisors, and factors as 2² × 3 × 5² × 7. Its proper divisors sum to 4,844, more than the number itself, making it an abundant number. Written other ways, in Roman numerals it is MMC and in binary, 100000110100.

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

Interestingness

★ ★ ★ ★ ☆

7 notable facts · grade B

2,088 2,089 2,090 2,091 2,092 2,093 2,094 2,095 2,096 2,097 2,098 2,099 2,100 2,101 2,102 2,103 2,104 2,105 2,106 2,107 2,108 2,109 2,110 2,111 2,112

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Historical context — 2100 AD

Current millennium spanning the years 2001 to 3000

The third millennium of the Anno Domini or Common Era is the current millennium spanning the years 2001 to 3000.

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: Friday
January 1, 2100
Ended on: Friday
December 31, 2100
Friday the 13ths: 1
One Friday the 13th this year.
Easter Sunday: March 28
Sunday, March 28, 2100
Decade: 2100s
2100–2109
Century: 21st century
2001–2100
Millennium: 3rd millennium
2001–3000
Years until: 74
74 years after 2026.
US presidential election: Yes
US holds a presidential election in years divisible by 4 starting from 1788.
Summer Olympics: Yes

In other calendars

Hebrew: 5860 / 5861 AM
Rosh Hashanah falls in September/October.
Islamic Hijri: 1523 / 1524 AH
Lunar calendar; year spans differ from Gregorian.
Chinese: Year of the zodiac:Metal zodiac:Monkey
Sexagenary cycle position 57 of 60. Lunar new year falls in late January / mid-February.
Buddhist Era: 2643 BE
Counted from the parinirvana of the Buddha (Theravada / Thai / Sri Lankan convention).
Persian Solar Hijri: 1478 / 1479 SH
Iranian calendar; Nowruz (new year) falls on the spring equinox.
Ethiopian: 2092 / 2093 ET
Year boundary at Enkutatash (September 11/12).
Indian National (Saka): 2022 / 2021 Saka
Indian national calendar; year starts in March.
Japanese: Reiwa 82
Reign-era counting from the start of each emperor's reign.

Properties

Parity: Even
Digit count: 4
Digit sum: 3
Digit product: 0
Digital root: 3
Palindrome: No
Bit width: 12 bits
Reversed: 12
Recamán's sequence: a(3,551) = 2,100
Square (n²): 4,410,000
Cube (n³): 9,261,000,000
Divisor count: 36
σ(n) — sum of divisors: 6,944
φ(n) — Euler's totient: 480
Sum of prime factors: 24

Primality

Prime factorization: 2 ² × 3 × 5 ² × 7

Nearest primes: 2,099 (−1) · 2,111 (+11)

Divisors & multiples

All divisors (36)

1 · 2 · 3 · 4 · 5 · 6 · 7 · 10 · 12 · 14 · 15 · 20 · 21 · 25 · 28 · 30 · 35 · 42 · 50 · 60 · 70 · 75 · 84 · 100 · 105 · 140 · 150 · 175 · 210 · 300 · 350 · 420 · 525 · 700 · 1050 (half) · 2100

Aliquot sum (sum of proper divisors): 4,844

Factor pairs (a × b = 2,100)

1 × 2100

2 × 1050

3 × 700

4 × 525

5 × 420

6 × 350

7 × 300

10 × 210

12 × 175

14 × 150

15 × 140

20 × 105

21 × 100

25 × 84

28 × 75

30 × 70

35 × 60

42 × 50

First multiples

2,100 · 4,200 (double) · 6,300 · 8,400 · 10,500 · 12,600 · 14,700 · 16,800 · 18,900 · 21,000

Sums & aliquot sequence

As consecutive integers: 699 + 700 + 701 418 + 419 + 420 + 421 + 422 297 + 298 + … + 303 259 + 260 + … + 266

Aliquot sequence: 2,100 → 4,844 → 4,900 → 7,469 → 1,939 → 285 → 195 → 141 → 51 → 21 → 11 → 1 → 0 — terminates at zero

Continued fraction of √n

√2,100 = [45; (1, 4, 1, 2, 1, 4, 1, 90)]

Period length 8 — the block in parentheses repeats forever.

Representations

In words: two thousand one hundred
Ordinal: 2100th
Roman numeral: MMC
Binary: 100000110100
Octal: 4064
Hexadecimal: 0x834
Base64: CDQ=
One's complement: 63,435 (16-bit)
Scientific notation: 2.1 × 10³
As a duration: 2,100 s = 35 minutes

In other bases

ternary (3) 2212210

quaternary (4) 200310

quinary (5) 31400

senary (6) 13420

septenary (7) 6060

nonary (9) 2783

undecimal (11) 163a

duodecimal (12) 1270

tridecimal (13) c57

tetradecimal (14) aa0

pentadecimal (15) 950

As an angle

2,100° = 5 × 360° + 300°

300° ≈ 5.236 rad

Compass bearing: WNW (west-northwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹 ·
Egyptian hieroglyphic: 𓆼𓆼𓍢
Greek (Milesian): ͵βρʹ
Mayan (base 20): 𝋥·𝋥·𝋠
Chinese: 二千一百
Chinese (financial): 貳仟壹佰

In other modern scripts

Eastern Arabic ٢١٠٠ Devanagari २१०० Bengali ২১০০ Tamil ௨௧௦௦ Thai ๒๑๐๐ Tibetan ༢༡༠༠ Khmer ២១០០ Lao ໒໑໐໐ Burmese ၂၁၀၀

Digit at this position in famous constants

π — Pi (π): Digit 2,100 = 0
e — Euler's number (e): Digit 2,100 = 3
φ — Golden ratio (φ): Digit 2,100 = 4
√2 — Pythagoras's (√2): Digit 2,100 = 6
ln 2 — Natural log of 2: Digit 2,100 = 2
γ — Euler-Mascheroni (γ): Digit 2,100 = 9

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 2100, here are decompositions:

11 + 2089 = 2100
13 + 2087 = 2100
17 + 2083 = 2100
19 + 2081 = 2100
31 + 2069 = 2100
37 + 2063 = 2100
47 + 2053 = 2100
61 + 2039 = 2100

Showing the first eight; more decompositions exist.

Unicode codepoint

࠴

Samaritan Punctuation Atmaau

U+0834

Other punctuation (Po)

UTF-8 encoding: E0 A0 B4 (3 bytes).

Lookup U+0834 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000834

RGB(0, 8, 52)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.8.52.

Address: 0.0.8.52
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.8.52

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

Musical pitch

Heard as a frequency, 2,100 Hz is closest to:

Concert pitch (A4 = 440 Hz): C7 (2093 Hz, +6¢)
Scientific pitch (C4 = 256 Hz): C7 (2048 Hz, +43¢)
Baroque pitch (A4 = 415 Hz): C♯7 (2091.5 Hz, +7¢)

Position in π

The digit sequence 2100 first appears in π at position 3,479 of the decimal expansion (the 3,479ordinal-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 2100 on Pi Search ↗