21,401
21,401 is a prime, odd.
21,401 (twenty-one thousand four hundred one) is an odd 5-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0x5399.
Interestingness
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 8
- Digit product
- 0
- Digital root
- 8
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 10,412
- Recamán's sequence
- a(41,037) = 21,401
- Square (n²)
- 458,002,801
- Cube (n³)
- 9,801,717,944,201
- Divisor count
- 2
- σ(n) — sum of divisors
- 21,402
- φ(n) — Euler's totient
- 21,400
Primality
21,401 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√21,401 = [146; (3, 2, 3, 1, 1, 2, 1, 1, 1, 6, 1, 2, 6, 1, 3, 1, 2, 2, 2, 1, 1, 1, 9, 2, …)]
Representations
- In words
- twenty-one thousand four hundred one
- Ordinal
- 21401st
- Binary
- 101001110011001
- Octal
- 51631
- Hexadecimal
- 0x5399
- Base64
- U5k=
- One's complement
- 44,134 (16-bit)
- Scientific notation
- 2.1401 × 10⁴
- As a duration
- 21,401 s = 5 hours, 56 minutes, 41 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓂍𓂍𓆼𓍢𓍢𓍢𓍢𓏺
- Greek (Milesian)
- ͵καυαʹ
- Mayan (base 20)
- 𝋢·𝋭·𝋪·𝋡
- Chinese
- 二萬一千四百零一
- Chinese (financial)
- 貳萬壹仟肆佰零壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 21,401 = 3
- e — Euler's number (e)
- Digit 21,401 = 8
- φ — Golden ratio (φ)
- Digit 21,401 = 9
- √2 — Pythagoras's (√2)
- Digit 21,401 = 0
- ln 2 — Natural log of 2
- Digit 21,401 = 1
- γ — Euler-Mascheroni (γ)
- Digit 21,401 = 2
Also seen as
UTF-8 encoding: E5 8E 99 (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.83.153.
- Address
- 0.0.83.153
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.83.153
Unspecified address (0.0.0.0/8) — "this network" placeholder.
The digit sequence 21401 first appears in π at position 160,003 of the decimal expansion (the 160,003ordinal-suffix:rd 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
- Prime numbers — The building blocks of arithmetic: what primes are, why they matter, and how we find them.
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.