21,420
21,420 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
- 2,412
- Recamán's sequence
- a(40,999) = 21,420
- Square (n²)
- 458,816,400
- Cube (n³)
- 9,827,847,288,000
- Divisor count
- 72
- σ(n) — sum of divisors
- 78,624
- φ(n) — Euler's totient
- 4,608
- Sum of prime factors
- 39
Primality
Prime factorization: 2 2 × 3 2 × 5 × 7 × 17
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand four hundred twenty
- Ordinal
- 21420th
- Binary
- 101001110101100
- Octal
- 51654
- Hexadecimal
- 0x53AC
- Base64
- U6w=
- One's complement
- 44,115 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹 ·
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓎆𓎆
- Greek (Milesian)
- ͵καυκʹ
- Mayan (base 20)
- 𝋢·𝋭·𝋫·𝋠
- Chinese
- 二萬一千四百二十
- Chinese (financial)
- 貳萬壹仟肆佰貳拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,420 = 9
- e — Euler's number (e)
- Digit 21,420 = 8
- φ — Golden ratio (φ)
- Digit 21,420 = 8
- √2 — Pythagoras's (√2)
- Digit 21,420 = 9
- ln 2 — Natural log of 2
- Digit 21,420 = 7
- γ — Euler-Mascheroni (γ)
- Digit 21,420 = 0
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21420, here are decompositions:
- 13 + 21407 = 21420
- 19 + 21401 = 21420
- 23 + 21397 = 21420
- 29 + 21391 = 21420
- 37 + 21383 = 21420
- 41 + 21379 = 21420
- 43 + 21377 = 21420
- 73 + 21347 = 21420
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 8E AC (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.172.
- Address
- 0.0.83.172
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.83.172
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21420 first appears in π at position 89,007 of the decimal expansion (the 89,007ordinal-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.