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Composite Number

345

345 is a odd composite number that follows 344 and precedes 346. It is composed of 8 distinct factors: 1, 3, 5, 15, 23, 69, 115, 345. Its prime factorization can be written as 3 × 5 × 23. 345 is classified as a deficient number based on the sum of its proper divisors. In computer science, 345 is represented as 101011001 in binary and 159 in hexadecimal. Historically, it is written as CCCXLV in Roman numerals.

Roman Numeral
CCCXLV
LatinClassic
Binary
101011001
Base 2
Hexadecimal
159
Base 16

Factor Analysis

8 Factors

Properties

ParityOdd
Perfect SquareNo
Perfect CubeNo
Digit Count3
Digit Sum12
Digital Root3
Sum of Factors576
Aliquot Sum231
ClassificationDeficient
Prime Factors3
SequencesComposite numbers, Deficient numbers
Prime Factorization

The prime factorization (3 × 5 × 23) reveals 3 prime building blocks.

Canonical form
3 × 5 × 23
3523
Divisibility Insights
  • Divisible by 2

    345 ends in 5, so it is odd.

  • Divisible by 3

    The digit sum 12 is a multiple of 3.

  • Divisible by 4

    The last two digits 45 are not divisible by 4.

  • Divisible by 5

    345 ends in 5, so it is divisible by 5.

  • Divisible by 6

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

  • Divisible by 9

    The digit sum 12 is not a multiple of 9.

  • Divisible by 10

    345 does not end in 0.

  • Divisible by 11

    The alternating digit sum 4 is not a multiple of 11.

Sequence Membership

Deficient classification and digit analytics place 345 within several notable number theory sequences:

Composite numbersDeficient numbers
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Deep dive

How 345 breaks down

345 carries 8 distinct factors and a digit signature of 12 (3 as the digital root). The deficient classification indicates that its proper divisors sum to 231, which stays below the number, offering a quick glimpse into its abundance profile.

Numeral conversions provide additional context: the binary form 101011001 supports bitwise reasoning, hexadecimal 159 aligns with computing notation, and the Roman numeral CCCXLV keeps the encyclopedic tradition alive. These attributes make 345 useful for math olympiad problems, puzzle design, and code challenges alike.

Context

Where 345 shows up

Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (340350) to tune search ranges, and educators feature 345 in worksheets about factor trees. Its binary footprint of length 9 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 345 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 345

Is 345 a prime number?

345 is composite with 8 total factors and the prime factorization 3 × 5 × 23.

What is the prime factorization of 345?

It breaks down as 3 × 5 × 23, multiplying the primes 3 × 5 × 23.

How is 345 represented in binary and hexadecimal?

345 converts to 101011001 in binary and 159 in hexadecimal, which are helpful for computer science applications.

Is 345 a perfect square, cube, or triangular number?

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

What are the digit sum and digital root of 345?

The digits sum to 12, producing a digital root of 3. These tests power divisibility shortcuts for 3 and 9.