128,021
128,021 is a prime, odd.
128,021 (one hundred twenty-eight thousand twenty-one) is an odd 6-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0x1F415.
Interestingness
Properties
- Parity
- Odd
- Digit count
- 6
- Digit sum
- 14
- Digit product
- 0
- Digital root
- 5
- Palindrome
- No
- Bit width
- 17 bits
- Reversed
- 120,821
- Square (n²)
- 16,389,376,441
- Cube (n³)
- 2,098,184,361,353,261
- Divisor count
- 2
- σ(n) — sum of divisors
- 128,022
- φ(n) — Euler's totient
- 128,020
Primality
128,021 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√128,021 = [357; (1, 4, 178, 1, 2, 2, 1, 178, 4, 1, 714)]
Period length 11 — the block in parentheses repeats forever.
Representations
- In words
- one hundred twenty-eight thousand twenty-one
- Ordinal
- 128021st
- Binary
- 11111010000010101
- Octal
- 372025
- Hexadecimal
- 0x1F415
- Base64
- AfQV
- One's complement
- 4,294,839,274 (32-bit)
- Scientific notation
- 1.28021 × 10⁵
- As a duration
- 128,021 s = 1 day, 11 hours, 33 minutes, 41 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆐𓂍𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓎆𓎆𓏺
- Greek (Milesian)
- ͵ρκηκαʹ
- Mayan (base 20)
- 𝋰·𝋠·𝋡·𝋡
- Chinese
- 一十二萬八千零二十一
- Chinese (financial)
- 壹拾貳萬捌仟零貳拾壹
Also seen as
UTF-8 encoding: F0 9F 90 95 (4 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.1.244.21.
- Address
- 0.1.244.21
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.1.244.21
Unspecified address (0.0.0.0/8) — "this network" placeholder.
This number falls in the range of US utility patent numbers. If it's a patent, it would be issued as US 128,021 and was likely granted around 1872.
Patent numbers below 100,000 are excluded as too ambiguous; modern numbering currently reaches roughly 12.5 million.
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.