855
855 is a odd composite number that follows 854 and precedes 856. It is composed of 12 distinct factors: 1, 3, 5, 9, 15, 19, 45, 57, 95, 171, 285, 855. Its prime factorization can be written as 3^2 × 5 × 19. 855 is classified as a deficient number based on the sum of its proper divisors. In computer science, 855 is represented as 1101010111 in binary and 357 in hexadecimal. Historically, it is written as DCCCLV in Roman numerals.
Factor Analysis
12 FactorsProperties
The prime factorization (3^2 × 5 × 19) reveals 4 prime building blocks.
Divisible by 2
855 ends in 5, so it is odd.
Divisible by 3
The digit sum 18 is a multiple of 3.
Divisible by 4
The last two digits 55 are not divisible by 4.
Divisible by 5
855 ends in 5, so it is divisible by 5.
Divisible by 6
A number must be divisible by 2 and 3 to pass the 6-test.
Divisible by 9
The digit sum 18 is a multiple of 9.
Divisible by 10
855 does not end in 0.
Divisible by 11
The alternating digit sum 8 is not a multiple of 11.
Deficient classification and digit analytics place 855 within several notable number theory sequences:
Timeline
Deep dive
How 855 breaks down
855 carries 12 distinct factors and a digit signature of 18 (9 as the digital root). The deficient classification indicates that its proper divisors sum to 705, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 1101010111 supports bitwise reasoning, hexadecimal 357 aligns with computing notation, and the Roman numeral DCCCLV keeps the encyclopedic tradition alive. These attributes make 855 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 855 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (850–860) to tune search ranges, and educators feature 855 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 855 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 855
Is 855 a prime number?
855 is composite with 12 total factors and the prime factorization 3^2 × 5 × 19.
What is the prime factorization of 855?
It breaks down as 3^2 × 5 × 19, multiplying the primes 3 × 3 × 5 × 19.
How is 855 represented in binary and hexadecimal?
855 converts to 1101010111 in binary and 357 in hexadecimal, which are helpful for computer science applications.
Is 855 a perfect square, cube, or triangular number?
855 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 855?
The digits sum to 18, producing a digital root of 9. These tests power divisibility shortcuts for 3 and 9.