25687

25687 is a positive integer that appears in various mathematical contexts. In decimal notation it is written as 25687, and it has a hexadecimal representation of 0x6457 and a binary representation of 110010001010111 (leading zeros removed).

Its prime factorization is 25687 = 17 × 1511, so the number is composite and, more specifically, a semiprime (the product of two primes). The factors are 17, which is a small prime, and 1511, which is also prime. This factorization implies that 25687 has exactly four divisors: 1, 17, 1511, and 25687.

Numerically, 25687 is odd and lies between 2^14 and 2^15. It is congruent to 3 modulo 4 and to 7 modulo 8, which explains certain arithmetical properties it cannot have—for example, it cannot be expressed as a sum of two squares because a prime factor congruent to 3 mod 4 appears to an odd power in its factorization.

Other simple representations include its digital root, which is 1 (the digits sum to 28, and 2+8 = 10, 1+0 = 1). The value is not a perfect square, since its square root is approximately 160.3, and it does not coincide with any small-power extension of 2.

In mathematical discussions, 25687 often serves as an example of a small semiprime and as a test case for factoring algorithms and modular arithmetic properties. See also: semiprime, prime factorization.