21,438
21,438 is a composite number, even.
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 18
- Digit product
- 192
- Digital root
- 9
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 83,412
- Recamán's sequence
- a(40,963) = 21,438
- Square (n²)
- 459,587,844
- Cube (n³)
- 9,852,644,199,672
- Divisor count
- 16
- σ(n) — sum of divisors
- 47,760
- φ(n) — Euler's totient
- 7,128
- Sum of prime factors
- 408
Primality
Prime factorization: 2 × 3 3 × 397
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand four hundred thirty-eight
- Ordinal
- 21438th
- Binary
- 101001110111110
- Octal
- 51676
- Hexadecimal
- 0x53BE
- Base64
- U74=
- One's complement
- 44,097 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓏺𓏺𓏺𓏺𓏺𓏺𓏺𓏺
- Greek (Milesian)
- ͵καυληʹ
- Mayan (base 20)
- 𝋢·𝋭·𝋫·𝋲
- Chinese
- 二萬一千四百三十八
- Chinese (financial)
- 貳萬壹仟肆佰參拾捌
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,438 = 6
- e — Euler's number (e)
- Digit 21,438 = 1
- φ — Golden ratio (φ)
- Digit 21,438 = 4
- √2 — Pythagoras's (√2)
- Digit 21,438 = 8
- ln 2 — Natural log of 2
- Digit 21,438 = 0
- γ — Euler-Mascheroni (γ)
- Digit 21,438 = 6
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21438, here are decompositions:
- 5 + 21433 = 21438
- 19 + 21419 = 21438
- 31 + 21407 = 21438
- 37 + 21401 = 21438
- 41 + 21397 = 21438
- 47 + 21391 = 21438
- 59 + 21379 = 21438
- 61 + 21377 = 21438
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 8E BE (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.190.
- Address
- 0.0.83.190
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.83.190
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21438 first appears in π at position 209,739 of the decimal expansion (the 209,739ordinal-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.