169
169 is a odd composite number that follows 168 and precedes 170. It is composed of 3 distinct factors: 1, 13, 169. Its prime factorization can be written as 13^2. 169 is classified as a deficient number based on the sum of its proper divisors. In computer science, 169 is represented as 10101001 in binary and A9 in hexadecimal. Historically, it is written as CLXIX in Roman numerals. It also belongs to the perfect square sequence.
Factor Analysis
3 FactorsProperties
The prime factorization (13^2) reveals 2 prime building blocks.
Divisible by 2
169 ends in 9, so it is odd.
Divisible by 3
The digit sum 16 is not a multiple of 3.
Divisible by 4
The last two digits 69 are not divisible by 4.
Divisible by 5
169 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 16 is not a multiple of 9.
Divisible by 10
169 does not end in 0.
Divisible by 11
The alternating digit sum 4 is not a multiple of 11.
Deficient classification and digit analytics place 169 within several notable number theory sequences:
Timeline
Deep dive
How 169 breaks down
169 carries 3 distinct factors and a digit signature of 16 (7 as the digital root). The deficient classification indicates that its proper divisors sum to 14, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 10101001 supports bitwise reasoning, hexadecimal A9 aligns with computing notation, and the Roman numeral CLXIX keeps the encyclopedic tradition alive. These attributes make 169 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 169 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (164–174) to tune search ranges, and educators feature 169 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, Perfect squares) help historians, numerologists, and trivia writers tie 169 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 169
Is 169 a prime number?
169 is composite with 3 total factors and the prime factorization 13^2.
What is the prime factorization of 169?
It breaks down as 13^2, multiplying the primes 13 × 13.
How is 169 represented in binary and hexadecimal?
169 converts to 10101001 in binary and A9 in hexadecimal, which are helpful for computer science applications.
Is 169 a perfect square, cube, or triangular number?
169 is a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 169?
The digits sum to 16, producing a digital root of 7. These tests power divisibility shortcuts for 3 and 9.