21,490
21,490 is a composite number, even.
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 16
- Digit product
- 0
- Digital root
- 7
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 9,412
- Recamán's sequence
- a(40,859) = 21,490
- Square (n²)
- 461,820,100
- Cube (n³)
- 9,924,513,949,000
- Divisor count
- 16
- σ(n) — sum of divisors
- 44,352
- φ(n) — Euler's totient
- 7,344
- Sum of prime factors
- 321
Primality
Prime factorization: 2 × 5 × 7 × 307
Divisors & multiples
Sums & aliquot sequence
Representations
- In words
- twenty-one thousand four hundred ninety
- Ordinal
- 21490th
- Binary
- 101001111110010
- Octal
- 51762
- Hexadecimal
- 0x53F2
- Base64
- U/I=
- One's complement
- 44,045 (16-bit)
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹𒁹𒁹 𒌋
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆
- Greek (Milesian)
- ͵καυϟʹ
- Mayan (base 20)
- 𝋢·𝋭·𝋮·𝋪
- Chinese
- 二萬一千四百九十
- Chinese (financial)
- 貳萬壹仟肆佰玖拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,490 = 0
- e — Euler's number (e)
- Digit 21,490 = 2
- φ — Golden ratio (φ)
- Digit 21,490 = 0
- √2 — Pythagoras's (√2)
- Digit 21,490 = 8
- ln 2 — Natural log of 2
- Digit 21,490 = 8
- γ — Euler-Mascheroni (γ)
- Digit 21,490 = 4
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21490, here are decompositions:
- 3 + 21487 = 21490
- 23 + 21467 = 21490
- 71 + 21419 = 21490
- 83 + 21407 = 21490
- 89 + 21401 = 21490
- 107 + 21383 = 21490
- 113 + 21377 = 21490
- 149 + 21341 = 21490
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 8F B2 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.242.
- Address
- 0.0.83.242
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.83.242
Unspecified address (0.0.0.0/8) — "this network" placeholder.
This passes the ABA routing number checksum and matches the Federal Reserve numbering scheme.
Banks operate many routing numbers per state and division; an unmatched checksum-valid number can still be a real RTN at a smaller institution.
The digit sequence 21490 first appears in π at position 39,744 of the decimal expansion (the 39,744ordinal-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.