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Composite Number

990

990 is a even composite number that follows 989 and precedes 991. It is composed of 24 distinct factors: 1, 2, 3, 5, 6, 9, 10, 11, 15, 18, 22, 30, 33, 45, 55, 66, 90, 99, 110, 165, 198, 330, 495, 990. Its prime factorization can be written as 2 × 3^2 × 5 × 11. 990 is classified as a abundant number based on the sum of its proper divisors. In computer science, 990 is represented as 1111011110 in binary and 3DE in hexadecimal. Historically, it is written as CMXC in Roman numerals. It also belongs to the triangular number sequence.

Roman Numeral
CMXC
LatinClassic
Binary
1111011110
Base 2
Hexadecimal
3DE
Base 16

Factor Analysis

24 Factors

Properties

ParityEven
Perfect SquareNo
Perfect CubeNo
Digit Count3
Digit Sum18
Digital Root9
Sum of Factors2808
Aliquot Sum1818
ClassificationAbundant
Prime Factors5
SequencesComposite numbers, Abundant numbers
Prime Factorization

The prime factorization (2 × 3^2 × 5 × 11) reveals 5 prime building blocks.

Canonical form
2 × 3^2 × 5 × 11
233511
Divisibility Insights
  • Divisible by 2

    990 ends in 0, so it is even.

  • Divisible by 3

    The digit sum 18 is a multiple of 3.

  • Divisible by 4

    The last two digits 90 are not divisible by 4.

  • Divisible by 5

    990 ends in 0, so it is divisible by 5.

  • Divisible by 6

    It meets the tests for both 2 and 3, so it is divisible by 6.

  • Divisible by 9

    The digit sum 18 is a multiple of 9.

  • Divisible by 10

    990 ends in 0.

  • Divisible by 11

    The alternating digit sum 0 is a multiple of 11.

Sequence Membership

Abundant classification and digit analytics place 990 within several notable number theory sequences:

Composite numbersAbundant numbersTriangular numbers
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Deep dive

How 990 breaks down

990 carries 24 distinct factors and a digit signature of 18 (9 as the digital root). The abundant classification indicates that its proper divisors sum to 1818, which exceeds the number, offering a quick glimpse into its abundance profile.

Numeral conversions provide additional context: the binary form 1111011110 supports bitwise reasoning, hexadecimal 3DE aligns with computing notation, and the Roman numeral CMXC keeps the encyclopedic tradition alive. These attributes make 990 useful for math olympiad problems, puzzle design, and code challenges alike.

Context

Where 990 shows up

Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (985995) to tune search ranges, and educators feature 990 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, Abundant numbers, Triangular numbers) help historians, numerologists, and trivia writers tie 990 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 990

Is 990 a prime number?

990 is composite with 24 total factors and the prime factorization 2 × 3^2 × 5 × 11.

What is the prime factorization of 990?

It breaks down as 2 × 3^2 × 5 × 11, multiplying the primes 2 × 3 × 3 × 5 × 11.

How is 990 represented in binary and hexadecimal?

990 converts to 1111011110 in binary and 3DE in hexadecimal, which are helpful for computer science applications.

Is 990 a perfect square, cube, or triangular number?

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

What are the digit sum and digital root of 990?

The digits sum to 18, producing a digital root of 9. These tests power divisibility shortcuts for 3 and 9.