245857

245857 is a six-digit natural number that lies between 245856 and 245858. In base-10 notation it has the prime factorization 245857 = 47 × 5231, making it a semiprime. Both 47 and 5231 are primes, so the number has exactly two prime factors counting multiplicity.

From a divisibility standpoint, 245857 is odd and not divisible by 3 or 5; the sum of its digits is 31, so it is not a multiple of 3 or 9. The digital sum reduces to a digital root of 4. The number is congruent to 1 modulo 4 and to 1 modulo 8.

As a semiprime, 245857 serves as a straightforward example in introductory number theory of a composite number that factors into exactly two primes. It does not have a widely noted mathematical constant or special naming associated with it, but its factorization illustrates basic concepts of primality and factorization that are foundational in the study of integers.

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