Live analysis

21,100

21,100 is a composite number, even.

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.).

Abundant Number Gapful Number Harshad / Niven Odious Number Pernicious Number Practical Number Recamán's Sequence Self Number Semiperfect Number

Properties

Parity: Even
Digit count: 5
Digit sum: 4
Digit product: 0
Digital root: 4
Palindrome: No
Bit width: 15 bits
Reversed: 112
Recamán's sequence: a(41,639) = 21,100
Square (n²): 445,210,000
Cube (n³): 9,393,931,000,000
Divisor count: 18
σ(n) — sum of divisors: 46,004
φ(n) — Euler's totient: 8,400
Sum of prime factors: 225

Primality

Prime factorization: 2 ² × 5 ² × 211

Nearest primes: 21,089 (−11) · 21,101 (+1)

Divisors & multiples

All divisors (18)

1 · 2 · 4 · 5 · 10 · 20 · 25 · 50 · 100 · 211 · 422 · 844 · 1055 · 2110 · 4220 · 5275 · 10550 (half) · 21100

Aliquot sum (sum of proper divisors): 24,904

Factor pairs (a × b = 21,100)

1 × 21100

2 × 10550

4 × 5275

5 × 4220

10 × 2110

20 × 1055

25 × 844

50 × 422

100 × 211

First multiples

21,100 · 42,200 (double) · 63,300 · 84,400 · 105,500 · 126,600 · 147,700 · 168,800 · 189,900 · 211,000

Sums & aliquot sequence

As consecutive integers: 4,218 + 4,219 + 4,220 + 4,221 + 4,222 2,634 + 2,635 + … + 2,641 832 + 833 + … + 856 508 + 509 + … + 547

Aliquot sequence: 21,100 → 24,904 → 26,216 → 25,084 → 18,820 → 20,744 → 18,166 → 10,058 → 5,494 → 3,074 → 1,786 → 1,094 → 550 → 566 → 286 → 218 → 112 — unresolved within range

Representations

In words: twenty-one thousand one hundred
Ordinal: 21100th
Binary: 101001001101100
Octal: 51154
Hexadecimal: 0x526C
Base64: Umw=
One's complement: 44,435 (16-bit)

In other bases

ternary (3) 1001221111

quaternary (4) 11021230

quinary (5) 1133400

senary (6) 241404

septenary (7) 115342

nonary (9) 31844

undecimal (11) 14942

duodecimal (12) 10264

tridecimal (13) 97b1

tetradecimal (14) 7992

pentadecimal (15) 63ba

Historical numeral systems

Babylonian (base 60): 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹 𒌋𒌋𒌋𒌋
Egyptian hieroglyphic: 𓂍𓂍𓆼𓍢
Greek (Milesian): ͵καρʹ
Mayan (base 20): 𝋢·𝋬·𝋯·𝋠
Chinese: 二萬一千一百
Chinese (financial): 貳萬壹仟壹佰

In other modern scripts

Eastern Arabic ٢١١٠٠ Devanagari २११०० Bengali ২১১০০ Tamil ௨௧௧௦௦ Thai ๒๑๑๐๐ Tibetan ༢༡༡༠༠ Khmer ២១១០០ Lao ໒໑໑໐໐ Burmese ၂၁၁၀၀

Digit at this position in famous constants

π — Pi (π): Digit 21,100 = 5
e — Euler's number (e): Digit 21,100 = 6
φ — Golden ratio (φ): Digit 21,100 = 8
√2 — Pythagoras's (√2): Digit 21,100 = 1
ln 2 — Natural log of 2: Digit 21,100 = 2
γ — Euler-Mascheroni (γ): Digit 21,100 = 3

Also seen as

Goldbach decomposition

Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21100, here are decompositions:

11 + 21089 = 21100
41 + 21059 = 21100
83 + 21017 = 21100
89 + 21011 = 21100
137 + 20963 = 21100
179 + 20921 = 21100
197 + 20903 = 21100
227 + 20873 = 21100

Showing the first eight; more decompositions exist.

Unicode codepoint

剬

CJK Unified Ideograph-526C

U+526C

Other letter (Lo)

UTF-8 encoding: E5 89 AC (3 bytes).

Lookup U+526C on Compart ↗ Lookup on FileFormat.Info ↗

Hex color

#00526C

RGB(0, 82, 108)

IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.108.

Address: 0.0.82.108
Class: reserved
IPv4-mapped IPv6: ::ffff:0.0.82.108

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

Position in π

The digit sequence 21100 first appears in π at position 169,069 of the decimal expansion (the 169,069ordinal-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 21100 on Pi Search ↗