1691
1691 is a odd composite number that follows 1690 and precedes 1692. It is composed of 4 distinct factors: 1, 19, 89, 1691. Its prime factorization can be written as 19 × 89. 1691 is classified as a deficient number based on the sum of its proper divisors. In computer science, 1691 is represented as 11010011011 in binary and 69B in hexadecimal. Historically, it is written as MDCXCI in Roman numerals.
Factor Analysis
4 FactorsProperties
The prime factorization (19 × 89) reveals 2 prime building blocks.
Divisible by 2
1691 ends in 1, so it is odd.
Divisible by 3
The digit sum 17 is not a multiple of 3.
Divisible by 4
The last two digits 91 are not divisible by 4.
Divisible by 5
1691 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
1691 does not end in 0.
Divisible by 11
The alternating digit sum 3 is not a multiple of 11.
Deficient classification and digit analytics place 1691 within several notable number theory sequences:
Timeline
Deep dive
How 1691 breaks down
1691 carries 4 distinct factors and a digit signature of 17 (8 as the digital root). The deficient classification indicates that its proper divisors sum to 109, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 11010011011 supports bitwise reasoning, hexadecimal 69B aligns with computing notation, and the Roman numeral MDCXCI keeps the encyclopedic tradition alive. These attributes make 1691 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 1691 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (1686–1696) to tune search ranges, and educators feature 1691 in worksheets about factor trees. Its binary footprint of length 11 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 1691 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 1691
Is 1691 a prime number?
1691 is composite with 4 total factors and the prime factorization 19 × 89.
What is the prime factorization of 1691?
It breaks down as 19 × 89, multiplying the primes 19 × 89.
How is 1691 represented in binary and hexadecimal?
1691 converts to 11010011011 in binary and 69B in hexadecimal, which are helpful for computer science applications.
Is 1691 a perfect square, cube, or triangular number?
1691 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 1691?
The digits sum to 17, producing a digital root of 8. These tests power divisibility shortcuts for 3 and 9.