N
NumberPedia
Menu

© 2025 NumberPedia

Composite Number

2661

2661 is a odd composite number that follows 2660 and precedes 2662. It is composed of 4 distinct factors: 1, 3, 887, 2661. Its prime factorization can be written as 3 × 887. 2661 is classified as a deficient number based on the sum of its proper divisors. In computer science, 2661 is represented as 101001100101 in binary and A65 in hexadecimal. Historically, it is written as MMDCLXI in Roman numerals.

Roman Numeral
MMDCLXI
LatinClassic
Binary
101001100101
Base 2
Hexadecimal
A65
Base 16

Factor Analysis

4 Factors

Properties

ParityOdd
Perfect SquareNo
Perfect CubeNo
Digit Count4
Digit Sum15
Digital Root6
Sum of Factors3552
Aliquot Sum891
ClassificationDeficient
Prime Factors2
SequencesComposite numbers, Deficient numbers
Prime Factorization

The prime factorization (3 × 887) reveals 2 prime building blocks.

Canonical form
3 × 887
3887
Divisibility Insights
  • Divisible by 2

    2661 ends in 1, so it is odd.

  • Divisible by 3

    The digit sum 15 is a multiple of 3.

  • Divisible by 4

    The last two digits 61 are not divisible by 4.

  • Divisible by 5

    2661 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 15 is not a multiple of 9.

  • Divisible by 10

    2661 does not end in 0.

  • Divisible by 11

    The alternating digit sum 1 is not a multiple of 11.

Sequence Membership

Deficient classification and digit analytics place 2661 within several notable number theory sequences:

Composite numbersDeficient numbers
Advertisement

Deep dive

How 2661 breaks down

2661 carries 4 distinct factors and a digit signature of 15 (6 as the digital root). The deficient classification indicates that its proper divisors sum to 891, which stays below the number, offering a quick glimpse into its abundance profile.

Numeral conversions provide additional context: the binary form 101001100101 supports bitwise reasoning, hexadecimal A65 aligns with computing notation, and the Roman numeral MMDCLXI keeps the encyclopedic tradition alive. These attributes make 2661 useful for math olympiad problems, puzzle design, and code challenges alike.

Context

Where 2661 shows up

Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (26562666) to tune search ranges, and educators feature 2661 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 2661 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 2661

Is 2661 a prime number?

2661 is composite with 4 total factors and the prime factorization 3 × 887.

What is the prime factorization of 2661?

It breaks down as 3 × 887, multiplying the primes 3 × 887.

How is 2661 represented in binary and hexadecimal?

2661 converts to 101001100101 in binary and A65 in hexadecimal, which are helpful for computer science applications.

Is 2661 a perfect square, cube, or triangular number?

2661 is not a perfect square, is not a perfect cube, and is not triangular.

What are the digit sum and digital root of 2661?

The digits sum to 15, producing a digital root of 6. These tests power divisibility shortcuts for 3 and 9.