209
209 is a odd composite number that follows 208 and precedes 210. It is composed of 4 distinct factors: 1, 11, 19, 209. Its prime factorization can be written as 11 × 19. 209 is classified as a deficient number based on the sum of its proper divisors. In computer science, 209 is represented as 11010001 in binary and D1 in hexadecimal. Historically, it is written as CCIX in Roman numerals.
Factor Analysis
4 FactorsProperties
The prime factorization (11 × 19) reveals 2 prime building blocks.
Divisible by 2
209 ends in 9, so it is odd.
Divisible by 3
The digit sum 11 is not a multiple of 3.
Divisible by 4
The last two digits 09 are not divisible by 4.
Divisible by 5
209 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 11 is not a multiple of 9.
Divisible by 10
209 does not end in 0.
Divisible by 11
The alternating digit sum 11 is a multiple of 11.
Deficient classification and digit analytics place 209 within several notable number theory sequences:
Timeline
Deep dive
How 209 breaks down
209 carries 4 distinct factors and a digit signature of 11 (2 as the digital root). The deficient classification indicates that its proper divisors sum to 31, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 11010001 supports bitwise reasoning, hexadecimal D1 aligns with computing notation, and the Roman numeral CCIX keeps the encyclopedic tradition alive. These attributes make 209 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 209 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (204–214) to tune search ranges, and educators feature 209 in worksheets about factor trees. Its binary footprint of length 8 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 209 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 209
Is 209 a prime number?
209 is composite with 4 total factors and the prime factorization 11 × 19.
What is the prime factorization of 209?
It breaks down as 11 × 19, multiplying the primes 11 × 19.
How is 209 represented in binary and hexadecimal?
209 converts to 11010001 in binary and D1 in hexadecimal, which are helpful for computer science applications.
Is 209 a perfect square, cube, or triangular number?
209 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 209?
The digits sum to 11, producing a digital root of 2. These tests power divisibility shortcuts for 3 and 9.