21,006
21,006 is a composite number, even.
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 9
- Digit product
- 0
- Digital root
- 9
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 60,012
- Recamán's sequence
- a(41,827) = 21,006
- Square (n²)
- 441,252,036
- Cube (n³)
- 9,268,940,268,216
- Divisor count
- 16
- σ(n) — sum of divisors
- 46,800
- φ(n) — Euler's totient
- 6,984
- Sum of prime factors
- 400
Primality
Prime factorization: 2 × 3 3 × 389
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand six
- Ordinal
- 21006th
- Binary
- 101001000001110
- Octal
- 51016
- Hexadecimal
- 0x520E
- Base64
- Ug4=
- One's complement
- 44,529 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋 𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καϛʹ
- Mayan (base 20)
- 𝋢·𝋬·𝋪·𝋦
- Chinese
- 二萬一千零六
- Chinese (financial)
- 貳萬壹仟零陸
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,006 = 0
- e — Euler's number (e)
- Digit 21,006 = 9
- φ — Golden ratio (φ)
- Digit 21,006 = 1
- √2 — Pythagoras's (√2)
- Digit 21,006 = 3
- ln 2 — Natural log of 2
- Digit 21,006 = 9
- γ — Euler-Mascheroni (γ)
- Digit 21,006 = 4
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21006, here are decompositions:
- 5 + 21001 = 21006
- 23 + 20983 = 21006
- 43 + 20963 = 21006
- 47 + 20959 = 21006
- 59 + 20947 = 21006
- 67 + 20939 = 21006
- 103 + 20903 = 21006
- 107 + 20899 = 21006
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 88 8E (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.14.
- Address
- 0.0.82.14
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.82.14
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21006 first appears in π at position 3,479 of the decimal expansion (the 3,479ordinal-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.