21,023
21,023 is a prime, odd.
21,023 (twenty-one thousand twenty-three) is an odd 5-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0x521F.
Interestingness
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 8
- Digit product
- 0
- Digital root
- 8
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 32,012
- Recamán's sequence
- a(41,793) = 21,023
- Square (n²)
- 441,966,529
- Cube (n³)
- 9,291,462,339,167
- Divisor count
- 2
- σ(n) — sum of divisors
- 21,024
- φ(n) — Euler's totient
- 21,022
Primality
21,023 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√21,023 = [144; (1, 143, 1, 288)]
Period length 4 — the block in parentheses repeats forever.
Representations
- In words
- twenty-one thousand twenty-three
- Ordinal
- 21023rd
- Binary
- 101001000011111
- Octal
- 51037
- Hexadecimal
- 0x521F
- Base64
- Uh8=
- One's complement
- 44,512 (16-bit)
- Scientific notation
- 2.1023 × 10⁴
- As a duration
- 21,023 s = 5 hours, 50 minutes, 23 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋 𒌋𒌋𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓎆𓎆𓏺𓏺𓏺
- Greek (Milesian)
- ͵κακγʹ
- Mayan (base 20)
- 𝋢·𝋬·𝋫·𝋣
- Chinese
- 二萬一千零二十三
- Chinese (financial)
- 貳萬壹仟零貳拾參
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,023 = 1
- e — Euler's number (e)
- Digit 21,023 = 1
- φ — Golden ratio (φ)
- Digit 21,023 = 6
- √2 — Pythagoras's (√2)
- Digit 21,023 = 3
- ln 2 — Natural log of 2
- Digit 21,023 = 2
- γ — Euler-Mascheroni (γ)
- Digit 21,023 = 7
Also seen as
UTF-8 encoding: E5 88 9F (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.31.
- Address
- 0.0.82.31
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.82.31
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21023 first appears in π at position 123,006 of the decimal expansion (the 123,006ordinal-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
- Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.