1291
1291 is a odd prime number that follows 1290 and precedes 1292. As a prime number, 1291 is only divisible by 1 and itself. It holds a unique position in the sequence of integers. Its prime factorization is simply 1291. 1291 is classified as a deficient number based on the sum of its proper divisors. In computer science, 1291 is represented as 10100001011 in binary and 50B in hexadecimal. Historically, it is written as MCCXCI in Roman numerals.
Factor Analysis
2 FactorsProperties
1291 is prime, so its only factors are 1 and 1291.
Divisible by 2
1291 ends in 1, so it is odd.
Divisible by 3
The digit sum 13 is not a multiple of 3.
Divisible by 4
The last two digits 91 are not divisible by 4.
Divisible by 5
1291 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 13 is not a multiple of 9.
Divisible by 10
1291 does not end in 0.
Divisible by 11
The alternating digit sum 7 is not a multiple of 11.
Deficient classification and digit analytics place 1291 within several notable number theory sequences:
Timeline
Deep dive
How 1291 breaks down
1291 carries 2 distinct factors and a digit signature of 13 (4 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 10100001011 supports bitwise reasoning, hexadecimal 50B aligns with computing notation, and the Roman numeral MCCXCI keeps the encyclopedic tradition alive. These attributes make 1291 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 1291 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (1286–1296) to tune search ranges, and educators feature 1291 in worksheets about prime identification. 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 (Prime numbers, Deficient numbers) help historians, numerologists, and trivia writers tie 1291 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 1291
Is 1291 a prime number?
1291 is prime, meaning it is only divisible by 1 and itself.
What is the prime factorization of 1291?
1291 is already prime, so the factorization is simply 1291.
How is 1291 represented in binary and hexadecimal?
1291 converts to 10100001011 in binary and 50B in hexadecimal, which are helpful for computer science applications.
Is 1291 a perfect square, cube, or triangular number?
1291 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 1291?
The digits sum to 13, producing a digital root of 4. These tests power divisibility shortcuts for 3 and 9.