19,980
19,980 is a composite number, even.
19,980 (nineteen thousand nine hundred eighty) is an even 5-digit number. It is a composite number with 48 divisors, and factors as 2² × 3³ × 5 × 37. Its proper divisors sum to 43,860, more than the number itself, making it an abundant number. Written other ways, in hexadecimal, 0x4E0C.
Interestingness
Properties
- Parity
- Even
- Digit count
- 5
- Digit sum
- 27
- Digit product
- 0
- Digital root
- 9
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 8,991
- Flips to (rotate 180°)
- 8,661
- Square (n²)
- 399,200,400
- Cube (n³)
- 7,976,023,992,000
- Divisor count
- 48
- σ(n) — sum of divisors
- 63,840
- φ(n) — Euler's totient
- 5,184
- Sum of prime factors
- 55
Primality
Prime factorization: 2 2 × 3 3 × 5 × 37
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√19,980 = [141; (2, 1, 5, 1, 3, 7, 1, 1, 2, 5, 2, 1, 2, 31, 25, 1, 2, 70, 2, 1, 25, 31, 2, 1, …)]
Period length 36 — the block in parentheses repeats forever.
Representations
- In words
- nineteen thousand nine hundred eighty
- Ordinal
- 19980th
- Binary
- 100111000001100
- Octal
- 47014
- Hexadecimal
- 0x4E0C
- Base64
- Tgw=
- One's complement
- 45,555 (16-bit)
- Scientific notation
- 1.998 × 10⁴
- As a duration
- 19,980 s = 5 hours, 33 minutes
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹 ·
- Egyptian hieroglyphic
- 𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆
- Greek (Milesian)
- ͵ιθϡπʹ
- Mayan (base 20)
- 𝋢·𝋩·𝋳·𝋠
- Chinese
- 一萬九千九百八十
- Chinese (financial)
- 壹萬玖仟玖佰捌拾
Digit at this position in famous constants
- π — Pi (π)
- Digit 19,980 = 4
- e — Euler's number (e)
- Digit 19,980 = 1
- φ — Golden ratio (φ)
- Digit 19,980 = 6
- √2 — Pythagoras's (√2)
- Digit 19,980 = 1
- ln 2 — Natural log of 2
- Digit 19,980 = 3
- γ — Euler-Mascheroni (γ)
- Digit 19,980 = 6
Also seen as
Goldbach's conjecture says every even integer greater than 2 is the sum of two primes. For 19980, here are decompositions:
- 7 + 19973 = 19980
- 17 + 19963 = 19980
- 19 + 19961 = 19980
- 31 + 19949 = 19980
- 43 + 19937 = 19980
- 53 + 19927 = 19980
- 61 + 19919 = 19980
- 67 + 19913 = 19980
Showing the first eight; more decompositions exist.
UTF-8 encoding: E4 B8 8C (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.78.12.
- Address
- 0.0.78.12
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.78.12
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 19,980 Hz is closest to:
- Concert pitch (A4 = 440 Hz): D♯10 (19912.1 Hz, +6¢)
- Scientific pitch (C4 = 256 Hz): D♯10 (19484 Hz, +44¢)
- Baroque pitch (A4 = 415 Hz): E10 (19897.5 Hz, +7¢)
The digit sequence 19980 first appears in π at position 124,852 of the decimal expansion (the 124,852ordinal-suffix:nd 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°.