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Number

21,211

21,211 is a prime, odd.

Arithmetic Number Deficient Number Odious Number Prime Recamán's Sequence Squarefree

Properties

Parity
Odd
Digit count
5
Digit sum
7
Digit product
4
Digital root
7
Palindrome
No
Bit width
15 bits
Reversed
11,212
Recamán's sequence
a(41,417) = 21,211
Square (n²)
449,906,521
Cube (n³)
9,542,967,216,931
Divisor count
2
σ(n) — sum of divisors
21,212
φ(n) — Euler's totient
21,210

Primality

21,211 is prime. It has exactly two divisors: 1 and itself.

Divisors & multiples

All divisors (2)
1 · 21211
Aliquot sum (sum of proper divisors): 1
Factor pairs (a × b = 21,211)
1 × 21211
First multiples
21,211 · 42,422 (double) · 63,633 · 84,844 · 106,055 · 127,266 · 148,477 · 169,688 · 190,899 · 212,110

Sums & aliquot sequence

As consecutive integers: 10,605 + 10,606

Representations

In words
twenty-one thousand two hundred eleven
Ordinal
21211th
Binary
101001011011011
Octal
51333
Hexadecimal
0x52DB
Base64
Uts=
One's complement
44,324 (16-bit)
In other bases
ternary (3) 1002002121
quaternary (4) 11023123
quinary (5) 1134321
senary (6) 242111
septenary (7) 115561
nonary (9) 32077
undecimal (11) 14a33
duodecimal (12) 10337
tridecimal (13) 9868
tetradecimal (14) 7a31
pentadecimal (15) 6441

Historical numeral systems

Babylonian (base 60)
𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹 𒌋𒌋𒌋𒁹
Egyptian hieroglyphic
𓂍𓂍𓆼𓍢𓍢𓎆𓏺
Greek (Milesian)
͵κασιαʹ
Mayan (base 20)
𝋢·𝋭·𝋠·𝋫
Chinese
二萬一千二百一十一
Chinese (financial)
貳萬壹仟貳佰壹拾壹
In other modern scripts
Eastern Arabic ٢١٢١١ Devanagari २१२११ Bengali ২১২১১ Tamil ௨௧௨௧௧ Thai ๒๑๒๑๑ Tibetan ༢༡༢༡༡ Khmer ២១២១១ Lao ໒໑໒໑໑ Burmese ၂၁၂၁၁

Digit at this position in famous constants

π — Pi (π)
Digit 21,211 = 4
e — Euler's number (e)
Digit 21,211 = 4
φ — Golden ratio (φ)
Digit 21,211 = 6
√2 — Pythagoras's (√2)
Digit 21,211 = 6
ln 2 — Natural log of 2
Digit 21,211 = 0
γ — Euler-Mascheroni (γ)
Digit 21,211 = 6

Also seen as

Prime neighborhood

Adjacent primes:

  • Previous prime: 21,193 (gap of 18)
  • Next prime: 21,221 (gap of 10)
Unicode codepoint
CJK Unified Ideograph-52Db
U+52DB
Other letter (Lo)

UTF-8 encoding: E5 8B 9B (3 bytes).

Hex color
#0052DB
RGB(0, 82, 219)
IPv4 address

As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.219.

Address
0.0.82.219
Class
reserved
IPv4-mapped IPv6
::ffff:0.0.82.219

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

Position in π

The digit sequence 21211 first appears in π at position 82,538 of the decimal expansion (the 82,538ordinal-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.