165
165 is a odd composite number that follows 164 and precedes 166. It is composed of 8 distinct factors: 1, 3, 5, 11, 15, 33, 55, 165. Its prime factorization can be written as 3 × 5 × 11. 165 is classified as a deficient number based on the sum of its proper divisors. In computer science, 165 is represented as 10100101 in binary and A5 in hexadecimal. Historically, it is written as CLXV in Roman numerals.
Factor Analysis
8 FactorsProperties
The prime factorization (3 × 5 × 11) reveals 3 prime building blocks.
Divisible by 2
165 ends in 5, so it is odd.
Divisible by 3
The digit sum 12 is a multiple of 3.
Divisible by 4
The last two digits 65 are not divisible by 4.
Divisible by 5
165 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 12 is not a multiple of 9.
Divisible by 10
165 does not end in 0.
Divisible by 11
The alternating digit sum 0 is a multiple of 11.
Deficient classification and digit analytics place 165 within several notable number theory sequences:
Timeline
Deep dive
How 165 breaks down
165 carries 8 distinct factors and a digit signature of 12 (3 as the digital root). The deficient classification indicates that its proper divisors sum to 123, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 10100101 supports bitwise reasoning, hexadecimal A5 aligns with computing notation, and the Roman numeral CLXV keeps the encyclopedic tradition alive. These attributes make 165 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 165 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (160–170) to tune search ranges, and educators feature 165 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 165 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 165
Is 165 a prime number?
165 is composite with 8 total factors and the prime factorization 3 × 5 × 11.
What is the prime factorization of 165?
It breaks down as 3 × 5 × 11, multiplying the primes 3 × 5 × 11.
How is 165 represented in binary and hexadecimal?
165 converts to 10100101 in binary and A5 in hexadecimal, which are helpful for computer science applications.
Is 165 a perfect square, cube, or triangular number?
165 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 165?
The digits sum to 12, producing a digital root of 3. These tests power divisibility shortcuts for 3 and 9.