13,821
13,821 is a composite number, odd.
13,821 (thirteen thousand eight hundred twenty-one) is an odd 5-digit number. It is a composite number with 8 divisors, and factors as 3 × 17 × 271. Written other ways, in hexadecimal, 0x35FD.
Interestingness
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 15
- Digit product
- 48
- Digital root
- 6
- Palindrome
- No
- Bit width
- 14 bits
- Reversed
- 12,831
- Recamán's sequence
- a(21,074) = 13,821
- Square (n²)
- 191,020,041
- Cube (n³)
- 2,640,087,986,661
- Divisor count
- 8
- σ(n) — sum of divisors
- 19,584
- φ(n) — Euler's totient
- 8,640
- Sum of prime factors
- 291
Primality
Prime factorization: 3 × 17 × 271
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√13,821 = [117; (1, 1, 3, 2, 15, 4, 4, 1, 3, 9, 7, 58, 1, 1, 1, 3, 1, 1, 1, 1, 3, 3, 4, 3, …)]
Period length 46 — the block in parentheses repeats forever.
Representations
- In words
- thirteen thousand eight hundred twenty-one
- Ordinal
- 13821st
- Binary
- 11010111111101
- Octal
- 32775
- Hexadecimal
- 0x35FD
- Base64
- Nf0=
- One's complement
- 51,714 (16-bit)
- Scientific notation
- 1.3821 × 10⁴
- As a duration
- 13,821 s = 3 hours, 50 minutes, 21 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋 𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓂍𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓏺
- Greek (Milesian)
- ͵ιγωκαʹ
- Mayan (base 20)
- 𝋡·𝋮·𝋫·𝋡
- Chinese
- 一萬三千八百二十一
- Chinese (financial)
- 壹萬參仟捌佰貳拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 13,821 = 2
- e — Euler's number (e)
- Digit 13,821 = 1
- φ — Golden ratio (φ)
- Digit 13,821 = 1
- √2 — Pythagoras's (√2)
- Digit 13,821 = 8
- ln 2 — Natural log of 2
- Digit 13,821 = 8
- γ — Euler-Mascheroni (γ)
- Digit 13,821 = 5
Also seen as
UTF-8 encoding: E3 97 BD (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.53.253.
- Address
- 0.0.53.253
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.53.253
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 13,821 Hz is closest to:
- Concert pitch (A4 = 440 Hz): A9 (14080 Hz, -32¢)
- Scientific pitch (C4 = 256 Hz): A9 (13777.2 Hz, +5¢)
- Baroque pitch (A4 = 415 Hz): A♯9 (14069.7 Hz, -31¢)
The digit sequence 13821 first appears in π at position 67,256 of the decimal expansion (the 67,256ordinal-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°.