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Composite Number

2191

2191 is a odd composite number that follows 2190 and precedes 2192. It is composed of 4 distinct factors: 1, 7, 313, 2191. Its prime factorization can be written as 7 × 313. 2191 is classified as a deficient number based on the sum of its proper divisors. In computer science, 2191 is represented as 100010001111 in binary and 88F in hexadecimal. Historically, it is written as MMCXCI in Roman numerals.

Roman Numeral
MMCXCI
LatinClassic
Binary
100010001111
Base 2
Hexadecimal
88F
Base 16

Factor Analysis

4 Factors

Properties

ParityOdd
Perfect SquareNo
Perfect CubeNo
Digit Count4
Digit Sum13
Digital Root4
Sum of Factors2512
Aliquot Sum321
ClassificationDeficient
Prime Factors2
SequencesComposite numbers, Deficient numbers
Prime Factorization

The prime factorization (7 × 313) reveals 2 prime building blocks.

Canonical form
7 × 313
7313
Divisibility Insights
  • Divisible by 2

    2191 ends in 1, so it is odd.

  • Divisible by 3

    The digit sum 13 is not a multiple of 3.

  • Divisible by 4

    The last two digits 91 are not divisible by 4.

  • Divisible by 5

    2191 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 13 is not a multiple of 9.

  • Divisible by 10

    2191 does not end in 0.

  • Divisible by 11

    The alternating digit sum 9 is not a multiple of 11.

Sequence Membership

Deficient classification and digit analytics place 2191 within several notable number theory sequences:

Composite numbersDeficient numbers
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Deep dive

How 2191 breaks down

2191 carries 4 distinct factors and a digit signature of 13 (4 as the digital root). The deficient classification indicates that its proper divisors sum to 321, which stays below the number, offering a quick glimpse into its abundance profile.

Numeral conversions provide additional context: the binary form 100010001111 supports bitwise reasoning, hexadecimal 88F aligns with computing notation, and the Roman numeral MMCXCI keeps the encyclopedic tradition alive. These attributes make 2191 useful for math olympiad problems, puzzle design, and code challenges alike.

Context

Where 2191 shows up

Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (21862196) to tune search ranges, and educators feature 2191 in worksheets about factor trees. Its binary footprint of length 12 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 2191 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 2191

Is 2191 a prime number?

2191 is composite with 4 total factors and the prime factorization 7 × 313.

What is the prime factorization of 2191?

It breaks down as 7 × 313, multiplying the primes 7 × 313.

How is 2191 represented in binary and hexadecimal?

2191 converts to 100010001111 in binary and 88F in hexadecimal, which are helpful for computer science applications.

Is 2191 a perfect square, cube, or triangular number?

2191 is not a perfect square, is not a perfect cube, and is not triangular.

What are the digit sum and digital root of 2191?

The digits sum to 13, producing a digital root of 4. These tests power divisibility shortcuts for 3 and 9.