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Composite Number

621

621 is a odd composite number that follows 620 and precedes 622. It is composed of 8 distinct factors: 1, 3, 9, 23, 27, 69, 207, 621. Its prime factorization can be written as 3^3 × 23. 621 is classified as a deficient number based on the sum of its proper divisors. In computer science, 621 is represented as 1001101101 in binary and 26D in hexadecimal. Historically, it is written as DCXXI in Roman numerals.

Roman Numeral
DCXXI
LatinClassic
Binary
1001101101
Base 2
Hexadecimal
26D
Base 16

Factor Analysis

8 Factors

Properties

ParityOdd
Perfect SquareNo
Perfect CubeNo
Digit Count3
Digit Sum9
Digital Root9
Sum of Factors960
Aliquot Sum339
ClassificationDeficient
Prime Factors4
SequencesComposite numbers, Deficient numbers
Prime Factorization

The prime factorization (3^3 × 23) reveals 4 prime building blocks.

Canonical form
3^3 × 23
33323
Divisibility Insights
  • Divisible by 2

    621 ends in 1, so it is odd.

  • Divisible by 3

    The digit sum 9 is a multiple of 3.

  • Divisible by 4

    The last two digits 21 are not divisible by 4.

  • Divisible by 5

    621 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 9 is a multiple of 9.

  • Divisible by 10

    621 does not end in 0.

  • Divisible by 11

    The alternating digit sum 5 is not a multiple of 11.

Sequence Membership

Deficient classification and digit analytics place 621 within several notable number theory sequences:

Composite numbersDeficient numbers
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Deep dive

How 621 breaks down

621 carries 8 distinct factors and a digit signature of 9 (9 as the digital root). The deficient classification indicates that its proper divisors sum to 339, which stays below the number, offering a quick glimpse into its abundance profile.

Numeral conversions provide additional context: the binary form 1001101101 supports bitwise reasoning, hexadecimal 26D aligns with computing notation, and the Roman numeral DCXXI keeps the encyclopedic tradition alive. These attributes make 621 useful for math olympiad problems, puzzle design, and code challenges alike.

Context

Where 621 shows up

Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (616626) to tune search ranges, and educators feature 621 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 621 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 621

Is 621 a prime number?

621 is composite with 8 total factors and the prime factorization 3^3 × 23.

What is the prime factorization of 621?

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

How is 621 represented in binary and hexadecimal?

621 converts to 1001101101 in binary and 26D in hexadecimal, which are helpful for computer science applications.

Is 621 a perfect square, cube, or triangular number?

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

What are the digit sum and digital root of 621?

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