20,720
20,720 is a composite number, even.
20,720 (twenty thousand seven hundred twenty) is an even 5-digit number. It is a composite number with 40 divisors, and factors as 2⁴ × 5 × 7 × 37. Its proper divisors sum to 35,824, more than the number itself, making it an abundant number. Written other ways, in hexadecimal, 0x50F0.
Interestingness
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 11
- Digit product
- 0
- Digital root
- 2
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 2,702
- Recamán's sequence
- a(42,399) = 20,720
- Square (n²)
- 429,318,400
- Cube (n³)
- 8,895,477,248,000
- Divisor count
- 40
- σ(n) — sum of divisors
- 56,544
- φ(n) — Euler's totient
- 6,912
- Sum of prime factors
- 57
Primality
Prime factorization: 2 4 × 5 × 7 × 37
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√20,720 = [143; (1, 16, 1, 286)]
Period length 4 — the block in parentheses repeats forever.
Representations
- In words
- twenty thousand seven hundred twenty
- Ordinal
- 20720th
- Binary
- 101000011110000
- Octal
- 50360
- Hexadecimal
- 0x50F0
- Base64
- UPA=
- One's complement
- 44,815 (16-bit)
- Scientific notation
- 2.072 × 10⁴
- As a duration
- 20,720 s = 5 hours, 45 minutes, 20 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹 𒌋𒌋
- Egyptian hieroglyphic
- 𓂍𓂍𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆
- Greek (Milesian)
- ͵κψκʹ
- Mayan (base 20)
- 𝋢·𝋫·𝋰·𝋠
- Chinese
- 二萬零七百二十
- Chinese (financial)
- 貳萬零柒佰貳拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 20,720 = 7
- e — Euler's number (e)
- Digit 20,720 = 9
- φ — Golden ratio (φ)
- Digit 20,720 = 1
- √2 — Pythagoras's (√2)
- Digit 20,720 = 2
- ln 2 — Natural log of 2
- Digit 20,720 = 4
- γ — Euler-Mascheroni (γ)
- Digit 20,720 = 8
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 20720, here are decompositions:
- 3 + 20717 = 20720
- 13 + 20707 = 20720
- 79 + 20641 = 20720
- 109 + 20611 = 20720
- 127 + 20593 = 20720
- 157 + 20563 = 20720
- 199 + 20521 = 20720
- 211 + 20509 = 20720
Showing the first eight; more decompositions exist.
UTF-8 encoding: E5 83 B0 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.80.240.
- Address
- 0.0.80.240
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.80.240
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 20720 first appears in π at position 44,219 of the decimal expansion (the 44,219ordinal-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
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.