225
225 is a odd composite number that follows 224 and precedes 226. It is composed of 9 distinct factors: 1, 3, 5, 9, 15, 25, 45, 75, 225. Its prime factorization can be written as 3^2 × 5^2. 225 is classified as a deficient number based on the sum of its proper divisors. In computer science, 225 is represented as 11100001 in binary and E1 in hexadecimal. Historically, it is written as CCXXV in Roman numerals. It also belongs to the perfect square sequence.
Factor Analysis
9 FactorsProperties
The prime factorization (3^2 × 5^2) reveals 4 prime building blocks.
Divisible by 2
225 ends in 5, so it is odd.
Divisible by 3
The digit sum 9 is a multiple of 3.
Divisible by 4
The last two digits 25 are not divisible by 4.
Divisible by 5
225 ends in 5, 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 9 is a multiple of 9.
Divisible by 10
225 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 225 within several notable number theory sequences:
Timeline
Deep dive
How 225 breaks down
225 carries 9 distinct factors and a digit signature of 9 (9 as the digital root). The deficient classification indicates that its proper divisors sum to 178, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 11100001 supports bitwise reasoning, hexadecimal E1 aligns with computing notation, and the Roman numeral CCXXV keeps the encyclopedic tradition alive. These attributes make 225 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 225 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (220–230) to tune search ranges, and educators feature 225 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 225 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 225
Is 225 a prime number?
225 is composite with 9 total factors and the prime factorization 3^2 × 5^2.
What is the prime factorization of 225?
It breaks down as 3^2 × 5^2, multiplying the primes 3 × 3 × 5 × 5.
How is 225 represented in binary and hexadecimal?
225 converts to 11100001 in binary and E1 in hexadecimal, which are helpful for computer science applications.
Is 225 a perfect square, cube, or triangular number?
225 is a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 225?
The digits sum to 9, producing a digital root of 9. These tests power divisibility shortcuts for 3 and 9.