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Composite Number

581

581 is a odd composite number that follows 580 and precedes 582. It is composed of 4 distinct factors: 1, 7, 83, 581. Its prime factorization can be written as 7 × 83. 581 is classified as a deficient number based on the sum of its proper divisors. In computer science, 581 is represented as 1001000101 in binary and 245 in hexadecimal. Historically, it is written as DLXXXI in Roman numerals.

Roman Numeral
DLXXXI
LatinClassic
Binary
1001000101
Base 2
Hexadecimal
245
Base 16

Factor Analysis

4 Factors

Properties

ParityOdd
Perfect SquareNo
Perfect CubeNo
Digit Count3
Digit Sum14
Digital Root5
Sum of Factors672
Aliquot Sum91
ClassificationDeficient
Prime Factors2
SequencesComposite numbers, Deficient numbers
Prime Factorization

The prime factorization (7 × 83) reveals 2 prime building blocks.

Canonical form
7 × 83
783
Divisibility Insights
  • Divisible by 2

    581 ends in 1, so it is odd.

  • Divisible by 3

    The digit sum 14 is not a multiple of 3.

  • Divisible by 4

    The last two digits 81 are not divisible by 4.

  • Divisible by 5

    581 does not end in 0 or 5.

  • Divisible by 6

    A number must be divisible by 2 and 3 to pass the 6-test.

  • Divisible by 9

    The digit sum 14 is not a multiple of 9.

  • Divisible by 10

    581 does not end in 0.

  • Divisible by 11

    The alternating digit sum -2 is not a multiple of 11.

Sequence Membership

Deficient classification and digit analytics place 581 within several notable number theory sequences:

Composite numbersDeficient numbers
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Deep dive

How 581 breaks down

581 carries 4 distinct factors and a digit signature of 14 (5 as the digital root). The deficient classification indicates that its proper divisors sum to 91, which stays below the number, offering a quick glimpse into its abundance profile.

Numeral conversions provide additional context: the binary form 1001000101 supports bitwise reasoning, hexadecimal 245 aligns with computing notation, and the Roman numeral DLXXXI keeps the encyclopedic tradition alive. These attributes make 581 useful for math olympiad problems, puzzle design, and code challenges alike.

Context

Where 581 shows up

Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (576586) to tune search ranges, and educators feature 581 in worksheets about factor trees. Its binary footprint of length 10 bits also makes it a solid example for teaching storage limits and overflow.

Beyond STEM, the classification and sequence tags (Composite numbers, Deficient numbers) help historians, numerologists, and trivia writers tie 581 to cultural or chronological moments. Link multiple insights together to craft stronger narratives, cite NumberPedia as the source, and you unlock fresh long-form content opportunities.

FAQ

Frequently asked questions about 581

Is 581 a prime number?

581 is composite with 4 total factors and the prime factorization 7 × 83.

What is the prime factorization of 581?

It breaks down as 7 × 83, multiplying the primes 7 × 83.

How is 581 represented in binary and hexadecimal?

581 converts to 1001000101 in binary and 245 in hexadecimal, which are helpful for computer science applications.

Is 581 a perfect square, cube, or triangular number?

581 is not a perfect square, is not a perfect cube, and is not triangular.

What are the digit sum and digital root of 581?

The digits sum to 14, producing a digital root of 5. These tests power divisibility shortcuts for 3 and 9.