2,591
2,591 is a prime, odd.
2,591 (two thousand five hundred ninety-one) is an odd 4-digit number. It is a prime number — divisible only by 1 and itself. Written other ways, in Roman numerals it is MMDXCI and in binary, 101000011111.
Interestingness
Properties
Primality
2,591 is prime. It has exactly two divisors: 1 and itself.
Divisors & multiples
Sums & aliquot sequence
Continued fraction of √n
√2,591 = [50; (1, 9, 5, 3, 1, 7, 14, 2, 2, 2, 2, 1, 6, 1, 1, 3, 2, 1, 1, 1, 2, 19, 1, 49, …)]
Period length 48 — the block in parentheses repeats forever.
Representations
- In words
- two thousand five hundred ninety-one
- Ordinal
- 2591st
- Roman numeral
- MMDXCI
- Binary
- 101000011111
- Octal
- 5037
- Hexadecimal
- 0xA1F
- Base64
- Ch8=
- One's complement
- 62,944 (16-bit)
- Scientific notation
- 2.591 × 10³
- As a duration
- 2,591 s = 43 minutes, 11 seconds
As an angle
Historical numeral systems
- Babylonian (base 60)
- 𒌋𒌋𒌋𒌋𒁹𒁹𒁹 𒌋𒁹
- Egyptian hieroglyphic
- 𓆼𓆼𓍢𓍢𓍢𓍢𓍢𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓎆𓏺
- Greek (Milesian)
- ͵βφϟαʹ
- Mayan (base 20)
- 𝋦·𝋩·𝋫
- Chinese
- 二千五百九十一
- Chinese (financial)
- 貳仟伍佰玖拾壹
Digit at this position in famous constants
- π — Pi (π)
- Digit 2,591 = 9
- e — Euler's number (e)
- Digit 2,591 = 1
- φ — Golden ratio (φ)
- Digit 2,591 = 6
- √2 — Pythagoras's (√2)
- Digit 2,591 = 1
- ln 2 — Natural log of 2
- Digit 2,591 = 0
- γ — Euler-Mascheroni (γ)
- Digit 2,591 = 9
Also seen as
UTF-8 encoding: E0 A8 9F (3 bytes).
As an unsigned 32-bit integer, this is the IPv4 address 0.0.10.31.
- Address
- 0.0.10.31
- Class
- reserved
- IPv4-mapped IPv6
- ::ffff:0.0.10.31
Unspecified address (0.0.0.0/8) — "this network" placeholder.
Heard as a frequency, 2,591 Hz is closest to:
- Concert pitch (A4 = 440 Hz): E7 (2637 Hz, -30¢)
- Scientific pitch (C4 = 256 Hz): E7 (2580.3 Hz, +7¢)
- Baroque pitch (A4 = 415 Hz): F7 (2635.1 Hz, -29¢)
The digit sequence 2591 first appears in π at position 6,169 of the decimal expansion (the 6,169ordinal-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
- 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.