21,004
21,004 is a composite number, even.
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 7
- Digit product
- 0
- Digital root
- 7
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 40,012
- Recamán's sequence
- a(41,831) = 21,004
- Square (n²)
- 441,168,016
- Cube (n³)
- 9,266,293,008,064
- Divisor count
- 12
- σ(n) — sum of divisors
- 37,800
- φ(n) — Euler's totient
- 10,208
- Sum of prime factors
- 152
Primality
Prime factorization: 2 2 × 59 × 89
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand four
- Ordinal
- 21004th
- Binary
- 101001000001100
- Octal
- 51014
- Hexadecimal
- 0x520C
- Base64
- Ugw=
- One's complement
- 44,531 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋 𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καδʹ
- Mayan (base 20)
- 𝋢·𝋬·𝋪·𝋤
- Chinese
- 二萬一千零四
- Chinese (financial)
- 貳萬壹仟零肆
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,004 = 0
- e — Euler's number (e)
- Digit 21,004 = 4
- φ — Golden ratio (φ)
- Digit 21,004 = 9
- √2 — Pythagoras's (√2)
- Digit 21,004 = 2
- ln 2 — Natural log of 2
- Digit 21,004 = 4
- γ — Euler-Mascheroni (γ)
- Digit 21,004 = 2
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21004, here are decompositions:
- 3 + 21001 = 21004
- 23 + 20981 = 21004
- 41 + 20963 = 21004
- 83 + 20921 = 21004
- 101 + 20903 = 21004
- 107 + 20897 = 21004
- 131 + 20873 = 21004
- 197 + 20807 = 21004
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 88 8C (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.12.
- Address
- 0.0.82.12
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.82.12
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21004 first appears in π at position 157,659 of the decimal expansion (the 157,659ordinal-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.