Number
81,001
81,001 is a prime, odd.
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 10
- Digit product
- 0
- Digital root
- 1
- Palindrome
- No
- Bit width
- 17 bits
- Reversed
- 10,018
- Flips to (rotate 180°)
- 10,018
- Recamán's sequence
- a(272,370) = 81,001
- Square (n²)
- 6,561,162,001
- Cube (n³)
- 531,460,683,243,001
- Divisor count
- 2
- σ(n) — sum of divisors
- 81,002
- φ(n) — Euler's totient
- 81,000
Primality
81,001 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Aliquot sum (sum of proper divisors):
1
First multiples
81,001
·
162,002
(double)
·
243,003
·
324,004
·
405,005
·
486,006
·
567,007
·
648,008
·
729,009
·
810,010
Sums & aliquot sequence
As a sum of two squares:
51² + 280²
As consecutive integers:
40,500 + 40,501
Representations
- In words
- eighty-one thousand one
- Ordinal
- 81001st
- Binary
- 10011110001101001
- Octal
- 236151
- Hexadecimal
- 0x13C69
- Base64
- ATxp
- One's complement
- 4,294,886,294 (32-bit)
In other bases
ternary (3)
11010010001
quaternary (4)
103301221
quinary (5)
10043001
senary (6)
1423001
septenary (7)
455104
nonary (9)
133101
undecimal (11)
55948
duodecimal (12)
3aa61
tridecimal (13)
2ab3b
tetradecimal (14)
2173b
pentadecimal (15)
19001
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒁹𒁹 𒌋𒌋𒌋 𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓂍𓂍𓂍𓂍𓂍𓂍𓆼𓏺
- Greek (Milesian)
- ͵πααʹ
- Mayan (base 20)
- 𝋪·𝋢·𝋪·𝋡
- Chinese
- 八萬一千零一
- Chinese (financial)
- 捌萬壹仟零壹
In other modern scripts
Eastern Arabic
٨١٠٠١
Devanagari
८१००१
Bengali
৮১০০১
Tamil
௮௧௦௦௧
Thai
๘๑๐๐๑
Tibetan
༨༡༠༠༡
Khmer
៨១០០១
Lao
໘໑໐໐໑
Burmese
၈၁၀၀၁
Digit at this position in famous constants
- π — Pi (π)
- Digit 81,001 = 3
- e — Euler's number (e)
- Digit 81,001 = 7
- φ — Golden ratio (φ)
- Digit 81,001 = 5
- √2 — Pythagoras's (√2)
- Digit 81,001 = 8
- ln 2 — Natural log of 2
- Digit 81,001 = 1
- γ — Euler-Mascheroni (γ)
- Digit 81,001 = 7
Also seen as
Unicode codepoint
Egyptian Hieroglyph-13C69
U+13C69
Other letter (Lo)
UTF-8 encoding: F0 93 B1 A9 (4 bytes).
Hex color
#013C69
RGB(1, 60, 105)
IPv4 address
As an unsigned 32-bit integer, this is the IPv4 address 0.1.60.105.
- Address
- 0.1.60.105
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.1.60.105
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Position in π
The digit sequence 81001 first appears in π at position 31,832 of the decimal expansion (the 31,832ordinal-suffix:nd 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.