16,991
16,991 is a composite number, odd.
16,991 (sixteen thousand nine hundred ninety-one) is an odd 5-digit number. It is a composite number with 4 divisors, and factors as 13 × 1,307. Written other ways, in hexadecimal, 0x425F.
Interestingness
Properties
- Parity
- Odd
- Digit count
- 5
- Digit sum
- 26
- Digit product
- 486
- Digital root
- 8
- Palindrome
- No
- Bit width
- 15 bits
- Reversed
- 19,961
- Flips to (rotate 180°)
- 16,691
- Recamán's sequence
- a(44,429) = 16,991
- Square (n²)
- 288,694,081
- Cube (n³)
- 4,905,201,130,271
- Divisor count
- 4
- σ(n) — sum of divisors
- 18,312
- φ(n) — Euler's totient
- 15,672
- Sum of prime factors
- 1,320
Primality
Prime factorization: 13 × 1307
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√16,991 = [130; (2, 1, 6, 5, 5, 1, 6, 1, 1, 1, 1, 3, 2, 2, 7, 25, 1, 14, 2, 1, 2, 10, 18, 1, …)]
Period length 52 — the block in parentheses repeats forever.
Representations
- In words
- sixteen thousand nine hundred ninety-one
- Ordinal
- 16991st
- Binary
- 100001001011111
- Octal
- 41137
- Hexadecimal
- 0x425F
- Base64
- Ql8=
- One's complement
- 48,544 (16-bit)
- Scientific notation
- 1.6991 × 10⁴
- As a duration
- 16,991 s = 4 hours, 43 minutes, 11 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒁹𒁹𒁹𒁹 𒌋𒌋𒌋𒌋𒁹𒁹𒁹 𒌋𒁹
- Egyptian hieroglyphic
- 𓂍𓆼𓆼𓆼𓆼𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵ιϛϡϟαʹ
- Mayan (base 20)
- 𝋢·𝋢·𝋩·𝋫
- Chinese
- 一萬六千九百九十一
- Chinese (financial)
- 壹萬陸仟玖佰玖拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 16,991 = 3
- e — Euler's number (e)
- Digit 16,991 = 8
- φ — Golden ratio (φ)
- Digit 16,991 = 7
- √2 — Pythagoras's (√2)
- Digit 16,991 = 4
- ln 2 — Natural log of 2
- Digit 16,991 = 8
- γ — Euler-Mascheroni (γ)
- Digit 16,991 = 4
Also seen as
UTF-8 encoding: E4 89 9F (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.66.95.
- Address
- 0.0.66.95
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.66.95
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 16,991 Hz is closest to:
- Concert pitch (A4 = 440 Hz): C10 (16744 Hz, +25¢)
- Scientific pitch (C4 = 256 Hz): C♯10 (17358.2 Hz, -37¢)
- Baroque pitch (A4 = 415 Hz): C♯10 (16731.8 Hz, +27¢)
The digit sequence 16991 first appears in π at position 130,169 of the decimal expansion (the 130,169ordinal-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
- Mayan numerals — Vigesimal dots-and-bars with a shell zero — one of the earliest true zeros.