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Composite Number

668

668 is a even composite number that follows 667 and precedes 669. It is composed of 6 distinct factors: 1, 2, 4, 167, 334, 668. Its prime factorization can be written as 2^2 × 167. 668 is classified as a deficient number based on the sum of its proper divisors. In computer science, 668 is represented as 1010011100 in binary and 29C in hexadecimal. Historically, it is written as DCLXVIII in Roman numerals.

Roman Numeral
DCLXVIII
LatinClassic
Binary
1010011100
Base 2
Hexadecimal
29C
Base 16

Factor Analysis

6 Factors

Properties

ParityEven
Perfect SquareNo
Perfect CubeNo
Digit Count3
Digit Sum20
Digital Root2
Sum of Factors1176
Aliquot Sum508
ClassificationDeficient
Prime Factors3
SequencesComposite numbers, Deficient numbers
Prime Factorization

The prime factorization (2^2 × 167) reveals 3 prime building blocks.

Canonical form
2^2 × 167
22167
Divisibility Insights
  • Divisible by 2

    668 ends in 8, so it is even.

  • Divisible by 3

    The digit sum 20 is not a multiple of 3.

  • Divisible by 4

    The last two digits 68 form a multiple of 4.

  • Divisible by 5

    668 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 20 is not a multiple of 9.

  • Divisible by 10

    668 does not end in 0.

  • Divisible by 11

    The alternating digit sum 8 is not a multiple of 11.

Sequence Membership

Deficient classification and digit analytics place 668 within several notable number theory sequences:

Composite numbersDeficient numbers
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Deep dive

How 668 breaks down

668 carries 6 distinct factors and a digit signature of 20 (2 as the digital root). The deficient classification indicates that its proper divisors sum to 508, which stays below the number, offering a quick glimpse into its abundance profile.

Numeral conversions provide additional context: the binary form 1010011100 supports bitwise reasoning, hexadecimal 29C aligns with computing notation, and the Roman numeral DCLXVIII keeps the encyclopedic tradition alive. These attributes make 668 useful for math olympiad problems, puzzle design, and code challenges alike.

Context

Where 668 shows up

Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (663673) to tune search ranges, and educators feature 668 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 668 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 668

Is 668 a prime number?

668 is composite with 6 total factors and the prime factorization 2^2 × 167.

What is the prime factorization of 668?

It breaks down as 2^2 × 167, multiplying the primes 2 × 2 × 167.

How is 668 represented in binary and hexadecimal?

668 converts to 1010011100 in binary and 29C in hexadecimal, which are helpful for computer science applications.

Is 668 a perfect square, cube, or triangular number?

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

What are the digit sum and digital root of 668?

The digits sum to 20, producing a digital root of 2. These tests power divisibility shortcuts for 3 and 9.