987,991
987,991 is a prime, odd.
987,991 (nine hundred eighty-seven thousand nine hundred ninety-one) is an odd 6-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in hexadecimal, 0xF1357.
Interestingness
Properties
- Parity
- Odd
- Digit count
- 6
- Digit sum
- 43
- Digit product
- 40,824
- Digital root
- 7
- Palindrome
- No
- Bit width
- 20 bits
- Reversed
- 199,789
- Recamán's sequence
- a(330,657) = 987,991
- Square (n²)
- 976,126,216,081
- Cube (n³)
- 964,403,916,352,083,271
- Divisor count
- 2
- σ(n) — sum of divisors
- 987,992
- φ(n) — Euler's totient
- 987,990
Primality
987,991 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√987,991 = [993; (1, 43, 5, 1, 1, 1, 3, 1, 1, 1, 9, 1, 1, 4, 6, 1, 1, 5, 1, 1, 1, 3, 38, 1, …)]
Representations
- In words
- nine hundred eighty-seven thousand nine hundred ninety-one
- Ordinal
- 987991st
- Binary
- 11110001001101010111
- Octal
- 3611527
- Hexadecimal
- 0xF1357
- Base64
- DxNX
- One's complement
- 4,293,979,304 (32-bit)
- Scientific notation
- 9.87991 × 10⁵
- As a duration
- 987,991 s = 11 days, 10 hours, 26 minutes, 31 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹𒁹𒁹𒁹 𒌋𒌋𒁹𒁹𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒁹
- Egyptian hieroglyphic
- 𓆐𓆐𓆐𓆐𓆐𓆐𓆐𓆐𓆐𓂍𓂍𓂍𓂍𓂍𓂍𓂍𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵ϡπζϡϟαʹ
- Chinese
- 九十八萬七千九百九十一
- Chinese (financial)
- 玖拾捌萬柒仟玖佰玖拾壹
Also seen as
As an unsigned 32-bit integer, this is the IPv4 address 0.15.19.87.
- Address
- 0.15.19.87
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.15.19.87
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 987,991 and was likely granted around 1911.
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.
- Egyptian hieroglyphic numerals — Seven hieroglyphs for every power of ten, from a single stroke to a million.