Live analysis

2,121

2,121 is a composite number, odd.

This number doesn't have a permanent NumberWiki page yet — what you see below is computed live. Pages get added to the permanent index when they're notable (years, primes, curated, etc.).

2,121 (two thousand one hundred twenty-one) is an odd 4-digit number. It is a composite number with 8 divisors, and factors as 3 × 7 × 101. Written other ways, in Roman numerals it is MMCXXI and in binary, 100001001001.

Arithmetic Number Consecutive Digits Cube-Free Deficient Number Evil Number Gapful Number Happy Number Recamán's Sequence Sphenic Number Squarefree Undulating Number

Interestingness

★ ★ ★ ★ ★

9 notable facts · grade A

2,109 2,110 2,111 2,112 2,113 2,114 2,115 2,116 2,117 2,118 2,119 2,120 2,121 2,122 2,123 2,124 2,125 2,126 2,127 2,128 2,129 2,130 2,131 2,132 2,133

less more

Properties

Parity: Odd
Digit count: 4
Digit sum: 6
Digit product: 4
Digital root: 6
Palindrome: No
Bit width: 12 bits
Reversed: 1,212
Recamán's sequence: a(3,509) = 2,121
Square (n²): 4,498,641
Cube (n³): 9,541,617,561
Divisor count: 8
σ(n) — sum of divisors: 3,264
φ(n) — Euler's totient: 1,200
Sum of prime factors: 111

Primality

Prime factorization: 3 × 7 × 101

Nearest primes: 2,113 (−8) · 2,129 (+8)

Divisors & multiples

All divisors (8)

1 · 3 · 7 · 21 · 101 · 303 · 707 · 2121

Aliquot sum (sum of proper divisors): 1,143

Factor pairs (a × b = 2,121)

1 × 2121

3 × 707

7 × 303

21 × 101

First multiples

2,121 · 4,242 (double) · 6,363 · 8,484 · 10,605 · 12,726 · 14,847 · 16,968 · 19,089 · 21,210

Sums & aliquot sequence

As consecutive integers: 1,060 + 1,061 706 + 707 + 708 351 + 352 + 353 + 354 + 355 + 356 300 + 301 + … + 306

Aliquot sequence: 2,121 → 1,143 → 521 → 1 → 0 — terminates at zero

Continued fraction of √n

√2,121 = [46; (18, 2, 2, 3, 3, 1, 1, 5, 5, 4, 5, 5, 1, 1, 3, 3, 2, 2, 18, 92)]

Period length 20 — the block in parentheses repeats forever.

Representations

In words: two thousand one hundred twenty-one
Ordinal: 2121st
Roman numeral: MMCXXI
Binary: 100001001001
Octal: 4111
Hexadecimal: 0x849
Base64: CEk=
One's complement: 63,414 (16-bit)
Scientific notation: 2.121 × 10³
As a duration: 2,121 s = 35 minutes, 21 seconds

In other bases

ternary (3) 2220120

quaternary (4) 201021

quinary (5) 31441

senary (6) 13453

septenary (7) 6120

nonary (9) 2816

undecimal (11) 1659

duodecimal (12) 1289

tridecimal (13) c72

tetradecimal (14) ab7

pentadecimal (15) 966

As an angle

2,121° = 5 × 360° + 321°

321° ≈ 5.603 rad

Compass bearing: NW (northwest)

Why does a circle have 360 degrees? →

Historical numeral systems

Babylonian (base 60): 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒁹
Egyptian hieroglyphic: 𓆼𓆼𓍢𓎆𓎆𓏺
Greek (Milesian): ͵βρκαʹ
Mayan (base 20): 𝋥·𝋦·𝋡
Chinese: 二千一百二十一
Chinese (financial): 貳仟壹佰貳拾壹

In other modern scripts

Eastern Arabic ٢١٢١ Devanagari २१२१ Bengali ২১২১ Tamil ௨௧௨௧ Thai ๒๑๒๑ Tibetan ༢༡༢༡ Khmer ២១២១ Lao ໒໑໒໑ Burmese ၂၁၂၁

Digit at this position in famous constants

π — Pi (π): Digit 2,121 = 3
e — Euler's number (e): Digit 2,121 = 3
φ — Golden ratio (φ): Digit 2,121 = 4
√2 — Pythagoras's (√2): Digit 2,121 = 9
ln 2 — Natural log of 2: Digit 2,121 = 3
γ — Euler-Mascheroni (γ): Digit 2,121 = 8

Also seen as

Unicode codepoint

ࡉ

Mandaic Letter Aksa

U+0849

Other letter (Lo)

UTF-8 encoding: E0 A1 89 (3 bytes).

Lookup U+0849 on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#000849

RGB(0, 8, 73)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.8.73.

Address: 0.0.8.73
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.8.73

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

Musical pitch

Heard as a frequency, 2,121 Hz is closest to:

Concert pitch (A4 = 440 Hz): C7 (2093 Hz, +23¢)
Scientific pitch (C4 = 256 Hz): C♯7 (2169.8 Hz, -39¢)
Baroque pitch (A4 = 415 Hz): C♯7 (2091.5 Hz, +24¢)

Position in π

The digit sequence 2121 first appears in π at position 33,803 of the decimal expansion (the 33,803ordinal-suffix:rd 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 2121 on Pi Search ↗