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Number

21,101

21,101 is a prime, odd.

Arithmetic Number Chen Prime Deficient Number Evil Number Happy Number Prime Pythagorean Prime Recamán's Sequence Sexy Prime Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
5
Digit product
0
Digital root
5
Palindrome
No
Bit width
15 bits
Reversed
10,112
Recamán's sequence
a(41,637) = 21,101
Square (n²)
445,252,201
Cube (n³)
9,395,266,693,301
Divisor count
2
σ(n) — sum of divisors
21,102
φ(n) — Euler's totient
21,100

Primality

21,101 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21101
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,101)
1 × 21101
First multiples
21,101 · 42,202 (double) · 63,303 · 84,404 · 105,505 · 126,606 · 147,707 · 168,808 · 189,909 · 211,010

Sums & aliquot sequence

As a sum of two squares: 74² + 125²
As consecutive integers: 10,550 + 10,551

Representations

In words
twenty-one thousand one hundred one
Ordinal
21101st
Binary
101001001101101
Octal
51155
Hexadecimal
0x526D
Base64
Um0=
One's complement
44,434 (16-bit)
In other bases
ternary (3) 1001221112
quaternary (4) 11021231
quinary (5) 1133401
senary (6) 241405
septenary (7) 115343
nonary (9) 31845
undecimal (11) 14943
duodecimal (12) 10265
tridecimal (13) 97b2
tetradecimal (14) 7993
pentadecimal (15) 63bb

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹 𒌋𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓍢𓏺
Greek (Milesian)
͵καραʹ
Mayan (base 20)
𝋢·𝋬·𝋯·𝋡
Chinese
二萬一千一百零一
Chinese (financial)
貳萬壹仟壹佰零壹
In other modern scripts
Eastern Arabic ٢١١٠١ Devanagari २११०१ Bengali ২১১০১ Tamil ௨௧௧௦௧ Thai ๒๑๑๐๑ Tibetan ༢༡༡༠༡ Khmer ២១១០១ Lao ໒໑໑໐໑ Burmese ၂၁၁၀၁

Digit at this position in famous constants

π — Pi (π)
Digit 21,101 = 5
e — Euler's number (e)
Digit 21,101 = 7
φ — Golden ratio (φ)
Digit 21,101 = 5
√2 — Pythagoras's (√2)
Digit 21,101 = 2
ln 2 — Natural log of 2
Digit 21,101 = 5
γ — Euler-Mascheroni (γ)
Digit 21,101 = 9

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,089 (gap of 12)
  • Next prime: 21,107 (gap of 6)

Pair status: sexy with 21107.

Unicode codepoint
CJK Unified Ideograph-526D
U+526D
Other letter (Lo)

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

Hex color
#00526D
RGB(0, 82, 109)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.109.

Address
0.0.82.109
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.82.109

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

Position in π

The digit sequence 21101 first appears in π at position 3,843 of the decimal expansion (the 3,843ordinal-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.