20
20 is a even composite number that follows 19 and precedes 21. It is composed of 6 distinct factors: 1, 2, 4, 5, 10, 20. Its prime factorization can be written as 2^2 × 5. 20 is classified as a abundant number based on the sum of its proper divisors. In computer science, 20 is represented as 10100 in binary and 14 in hexadecimal. Historically, it is written as XX in Roman numerals.
Factor Analysis
6 FactorsProperties
The prime factorization (2^2 × 5) reveals 3 prime building blocks.
Divisible by 2
20 ends in 0, so it is even.
Divisible by 3
The digit sum 2 is not a multiple of 3.
Divisible by 4
The last two digits 20 form a multiple of 4.
Divisible by 5
20 ends in 0, 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 2 is not a multiple of 9.
Divisible by 10
20 ends in 0.
Divisible by 11
The alternating digit sum 2 is not a multiple of 11.
Abundant classification and digit analytics place 20 within several notable number theory sequences:
Timeline
Deep dive
How 20 breaks down
20 carries 6 distinct factors and a digit signature of 2 (2 as the digital root). The abundant classification indicates that its proper divisors sum to 22, which exceeds the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 10100 supports bitwise reasoning, hexadecimal 14 aligns with computing notation, and the Roman numeral XX keeps the encyclopedic tradition alive. These attributes make 20 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 20 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (15–25) to tune search ranges, and educators feature 20 in worksheets about factor trees. Its binary footprint of length 5 bits also makes it a solid example for teaching storage limits and overflow.
Beyond STEM, the classification and sequence tags (Composite numbers, Abundant numbers) help historians, numerologists, and trivia writers tie 20 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 20
Is 20 a prime number?
20 is composite with 6 total factors and the prime factorization 2^2 × 5.
What is the prime factorization of 20?
It breaks down as 2^2 × 5, multiplying the primes 2 × 2 × 5.
How is 20 represented in binary and hexadecimal?
20 converts to 10100 in binary and 14 in hexadecimal, which are helpful for computer science applications.
Is 20 a perfect square, cube, or triangular number?
20 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 20?
The digits sum to 2, producing a digital root of 2. These tests power divisibility shortcuts for 3 and 9.