21,164
21,164 is a composite number, even.
21,164 (twenty-one thousand one hundred sixty-four) is an even 5-digit number. It is a composite number with 24 divisors, and factors as 2² × 11 × 13 × 37. Its proper divisors sum to 23,524, more than the number itself, making it an abundant number. Written other ways, in hexadecimal, 0x52AC.
Interestingness
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 14
- Digit product
- 48
- Digital root
- 5
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 46,112
- Recamán's sequence
- a(41,511) = 21,164
- Square (n²)
- 447,914,896
- Cube (n³)
- 9,479,670,858,944
- Divisor count
- 24
- σ(n) — sum of divisors
- 44,688
- φ(n) — Euler's totient
- 8,640
- Sum of prime factors
- 65
Primality
Prime factorization: 2 2 × 11 × 13 × 37
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√21,164 = [145; (2, 11, 7, 5, 2, 1, 6, 1, 1, 2, 2, 1, 2, 72, 2, 1, 2, 2, 1, 1, 6, 1, 2, 5, …)]
Period length 28 — the block in parentheses repeats forever.
Representations
- In words
- twenty-one thousand one hundred sixty-four
- Ordinal
- 21164th
- Binary
- 101001010101100
- Octal
- 51254
- Hexadecimal
- 0x52AC
- Base64
- Uqw=
- One's complement
- 44,371 (16-bit)
- Scientific notation
- 2.1164 × 10⁴
- As a duration
- 21,164 s = 5 hours, 52 minutes, 44 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καρξδʹ
- Mayan (base 20)
- 𝋢·𝋬·𝋲·𝋤
- Chinese
- 二萬一千一百六十四
- Chinese (financial)
- 貳萬壹仟壹佰陸拾肆
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,164 = 4
- e — Euler's number (e)
- Digit 21,164 = 7
- φ — Golden ratio (φ)
- Digit 21,164 = 2
- √2 — Pythagoras's (√2)
- Digit 21,164 = 7
- ln 2 — Natural log of 2
- Digit 21,164 = 3
- γ — Euler-Mascheroni (γ)
- Digit 21,164 = 8
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21164, here are decompositions:
- 7 + 21157 = 21164
- 43 + 21121 = 21164
- 97 + 21067 = 21164
- 103 + 21061 = 21164
- 151 + 21013 = 21164
- 163 + 21001 = 21164
- 181 + 20983 = 21164
- 277 + 20887 = 21164
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 8A AC (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.172.
- Address
- 0.0.82.172
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.82.172
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21164 first appears in π at position 84,874 of the decimal expansion (the 84,874ordinal-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.
Related reading
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.