Live analysis
21,009
21,009 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.).
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 12
- Digit product
- 0
- Digital root
- 3
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 90,012
- Recamán's sequence
- a(41,821) = 21,009
- Square (n²)
- 441,378,081
- Cube (n³)
- 9,272,912,103,729
- Divisor count
- 8
- σ(n) — sum of divisors
- 28,800
- φ(n) — Euler's totient
- 13,616
- Sum of prime factors
- 199
Primality
Prime factorization: 3 × 47 × 149
Divisors & multiples
Aliquot sum (sum of proper divisors):
7,791
First multiples
21,009
·
42,018
(double)
·
63,027
·
84,036
·
105,045
·
126,054
·
147,063
·
168,072
·
189,081
·
210,090
Sums & aliquot sequence
As consecutive integers:
10,504 + 10,505
7,002 + 7,003 + 7,004
3,499 + 3,500 + 3,501 + 3,502 + 3,503 + 3,504
424 + 425 + … + 470
Aliquot sequence:
21,009 → 7,791 → 4,521 → 2,103 → 705 → 447 → 153 → 81 → 40 → 50 → 43 → 1 → 0
— terminates at zero
Representations
- In words
- twenty-one thousand nine
- Ordinal
- 21009th
- Binary
- 101001000010001
- Octal
- 51021
- Hexadecimal
- 0x5211
- Base64
- UhE=
- One's complement
- 44,526 (16-bit)
In other bases
ternary (3)
1001211010
quaternary (4)
11020101
quinary (5)
1133014
senary (6)
241133
septenary (7)
115152
nonary (9)
31733
undecimal (11)
1486a
duodecimal (12)
101a9
tridecimal (13)
9741
tetradecimal (14)
7929
pentadecimal (15)
6359
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋 𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καθʹ
- Mayan (base 20)
- 𝋢·𝋬·𝋪·𝋩
- Chinese
- 二萬一千零九
- Chinese (financial)
- 貳萬壹仟零玖
In other modern scripts
Eastern Arabic
٢١٠٠٩
Devanagari
२१००९
Bengali
২১০০৯
Tamil
௨௧௦௦௯
Thai
๒๑๐๐๙
Tibetan
༢༡༠༠༩
Khmer
២១០០៩
Lao
໒໑໐໐໙
Burmese
၂၁၀၀၉
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,009 = 2
- e — Euler's number (e)
- Digit 21,009 = 6
- φ — Golden ratio (φ)
- Digit 21,009 = 3
- √2 — Pythagoras's (√2)
- Digit 21,009 = 4
- ln 2 — Natural log of 2
- Digit 21,009 = 4
- γ — Euler-Mascheroni (γ)
- Digit 21,009 = 9
Also seen as
Unicode codepoint
刑
CJK Unified Ideograph-5211
U+5211
Other letter (Lo)
UTF-8 encoding: E5 88 91 (3 bytes).
Hex color
#005211
RGB(0, 82, 17)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.17.
- Address
- 0.0.82.17
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.82.17
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Position in π
The digit sequence 21009 first appears in π at position 135,759 of the decimal expansion (the 135,759ordinal-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.