21,072
21,072 is a composite number, even.
21,072 (twenty-one thousand seventy-two) is an even 5-digit number. It is a composite number with 20 divisors, and factors as 2⁴ × 3 × 439. Its proper divisors sum to 33,488, more than the number itself, making it an abundant number. Written other ways, in hexadecimal, 0x5250.
Interestingness
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 12
- Digit product
- 0
- Digital root
- 3
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 27,012
- Recamán's sequence
- a(41,695) = 21,072
- Square (n²)
- 444,029,184
- Cube (n³)
- 9,356,582,965,248
- Divisor count
- 20
- σ(n) — sum of divisors
- 54,560
- φ(n) — Euler's totient
- 7,008
- Sum of prime factors
- 450
Primality
Prime factorization: 2 4 × 3 × 439
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√21,072 = [145; (6, 5, 1, 3, 7, 5, 2, 4, 12, 2, 1, 1, 23, 1, 1, 2, 12, 4, 2, 5, 7, 3, 1, 5, …)]
Period length 26 — the block in parentheses repeats forever.
Representations
- In words
- twenty-one thousand seventy-two
- Ordinal
- 21072nd
- Binary
- 101001001010000
- Octal
- 51120
- Hexadecimal
- 0x5250
- Base64
- UlA=
- One's complement
- 44,463 (16-bit)
- Scientific notation
- 2.1072 × 10⁴
- As a duration
- 21,072 s = 5 hours, 51 minutes, 12 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹 𒌋𒁹𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺𓏺
- Greek (Milesian)
- ͵καοβʹ
- Mayan (base 20)
- 𝋢·𝋬·𝋭·𝋬
- Chinese
- 二萬一千零七十二
- Chinese (financial)
- 貳萬壹仟零柒拾貳
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,072 = 4
- e — Euler's number (e)
- Digit 21,072 = 2
- φ — Golden ratio (φ)
- Digit 21,072 = 9
- √2 — Pythagoras's (√2)
- Digit 21,072 = 6
- ln 2 — Natural log of 2
- Digit 21,072 = 4
- γ — Euler-Mascheroni (γ)
- Digit 21,072 = 8
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 21072, here are decompositions:
- 5 + 21067 = 21072
- 11 + 21061 = 21072
- 13 + 21059 = 21072
- 41 + 21031 = 21072
- 53 + 21019 = 21072
- 59 + 21013 = 21072
- 61 + 21011 = 21072
- 71 + 21001 = 21072
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 89 90 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.82.80.
- Address
- 0.0.82.80
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.82.80
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21072 first appears in π at position 19,257 of the decimal expansion (the 19,257ordinal-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
- Babylonian numerals — The base-60 cuneiform system that gave us 60 minutes, 60 seconds, and 360°.