809
809 is a odd prime number that follows 808 and precedes 810. As a prime number, 809 is only divisible by 1 and itself. It holds a unique position in the sequence of integers. Its prime factorization is simply 809. 809 is classified as a deficient number based on the sum of its proper divisors. In computer science, 809 is represented as 1100101001 in binary and 329 in hexadecimal. Historically, it is written as DCCCIX in Roman numerals.
Factor Analysis
2 FactorsProperties
809 is prime, so its only factors are 1 and 809.
Divisible by 2
809 ends in 9, so it is odd.
Divisible by 3
The digit sum 17 is not a multiple of 3.
Divisible by 4
The last two digits 09 are not divisible by 4.
Divisible by 5
809 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 17 is not a multiple of 9.
Divisible by 10
809 does not end in 0.
Divisible by 11
The alternating digit sum 17 is not a multiple of 11.
Deficient classification and digit analytics place 809 within several notable number theory sequences:
Timeline
Deep dive
How 809 breaks down
809 carries 2 distinct factors and a digit signature of 17 (8 as the digital root). The deficient classification indicates that its proper divisors sum to 1, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 1100101001 supports bitwise reasoning, hexadecimal 329 aligns with computing notation, and the Roman numeral DCCCIX keeps the encyclopedic tradition alive. These attributes make 809 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 809 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (804–814) to tune search ranges, and educators feature 809 in worksheets about prime identification. 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 (Prime numbers, Deficient numbers) help historians, numerologists, and trivia writers tie 809 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 809
Is 809 a prime number?
809 is prime, meaning it is only divisible by 1 and itself.
What is the prime factorization of 809?
809 is already prime, so the factorization is simply 809.
How is 809 represented in binary and hexadecimal?
809 converts to 1100101001 in binary and 329 in hexadecimal, which are helpful for computer science applications.
Is 809 a perfect square, cube, or triangular number?
809 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 809?
The digits sum to 17, producing a digital root of 8. These tests power divisibility shortcuts for 3 and 9.