87
87 is a odd composite number that follows 86 and precedes 88. It is composed of 4 distinct factors: 1, 3, 29, 87. Its prime factorization can be written as 3 × 29. 87 is classified as a deficient number based on the sum of its proper divisors. In computer science, 87 is represented as 1010111 in binary and 57 in hexadecimal. Historically, it is written as LXXXVII in Roman numerals.
Factor Analysis
4 FactorsProperties
The prime factorization (3 × 29) reveals 2 prime building blocks.
Divisible by 2
87 ends in 7, so it is odd.
Divisible by 3
The digit sum 15 is a multiple of 3.
Divisible by 4
The last two digits 87 are not divisible by 4.
Divisible by 5
87 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
87 does not end in 0.
Divisible by 11
The alternating digit sum 1 is not a multiple of 11.
Deficient classification and digit analytics place 87 within several notable number theory sequences:
Timeline
Deep dive
How 87 breaks down
87 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 33, which stays below the number, offering a quick glimpse into its abundance profile.
Numeral conversions provide additional context: the binary form 1010111 supports bitwise reasoning, hexadecimal 57 aligns with computing notation, and the Roman numeral LXXXVII keeps the encyclopedic tradition alive. These attributes make 87 useful for math olympiad problems, puzzle design, and code challenges alike.
Context
Where 87 shows up
Engineers lean on the divisibility profile when sizing circuits, mod designers use neighboring values (82–92) to tune search ranges, and educators feature 87 in worksheets about factor trees. Its binary footprint of length 7 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 87 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 87
Is 87 a prime number?
87 is composite with 4 total factors and the prime factorization 3 × 29.
What is the prime factorization of 87?
It breaks down as 3 × 29, multiplying the primes 3 × 29.
How is 87 represented in binary and hexadecimal?
87 converts to 1010111 in binary and 57 in hexadecimal, which are helpful for computer science applications.
Is 87 a perfect square, cube, or triangular number?
87 is not a perfect square, is not a perfect cube, and is not triangular.
What are the digit sum and digital root of 87?
The digits sum to 15, producing a digital root of 6. These tests power divisibility shortcuts for 3 and 9.