3921
3921 is a odd composite number that follows 3920 and precedes 3922. It is composed of 4 distinct factors: 1, 3, 1307, 3921. Its prime factorization can be written as 3 × 1307. 3921 is classified as a deficient number based on the sum of its proper divisors. In computer science, 3921 is represented as 111101010001 in binary and F51 in hexadecimal. Historically, it is written as MMMCMXXI in Roman numerals.
Factor Analysis
4 FactorsProperties
The prime factorization (3 × 1307) reveals 2 prime building blocks.
Divisible by 2
3921 ends in 1, so it is odd.
Divisible by 3
The digit sum 15 is a multiple of 3.
Divisible by 4
The last two digits 21 are not divisible by 4.
Divisible by 5
3921 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 15 is not a multiple of 9.
Divisible by 10
3921 does not end in 0.
Divisible by 11
The alternating digit sum -5 is not a multiple of 11.
Deficient classification and digit analytics place 3921 within several notable number theory sequences:
Timeline
Deep dive
How 3921 breaks down
3921 carries 4 distinct factors and a digit signature of 15 (6 as the digital root). The deficient classification indicates that its proper divisors sum to 1311, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 111101010001 supports bitwise reasoning, hexadecimal F51 aligns with computing notation, and the Roman numeral MMMCMXXI keeps the encyclopedic tradition alive. These attributes make 3921 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 3921 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (3916–3926) to tune search ranges, and educators feature 3921 in worksheets about factor trees. Its binary footprint of length 12 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 3921 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 3921
Is 3921 a prime number?
3921 is composite with 4 total factors and the prime factorization 3 × 1307.
What is the prime factorization of 3921?
It breaks down as 3 × 1307, multiplying the primes 3 × 1307.
How is 3921 represented in binary and hexadecimal?
3921 converts to 111101010001 in binary and F51 in hexadecimal, which are helpful for computer science applications.
Is 3921 a perfect square, cube, or triangular number?
3921 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 3921?
The digits sum to 15, producing a digital root of 6. These tests power divisibility shortcuts for 3 and 9.