257638497 has 4 divisors (see below), whose sum is σ = 343518000. Its totient is φ = 171758996.

The previous prime is 257638463. The next prime is 257638529. The reversal of 257638497 is 794836752.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 257638497 - 2²⁷ = 123420769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (257638397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42939747 + ... + 42939752.

It is an arithmetic number, because the mean of its divisors is an integer number (85879500).

Almost surely, 2^257638497 is an apocalyptic number.

It is an amenable number.

257638497 is a deficient number, since it is larger than the sum of its proper divisors (85879503).

257638497 is an equidigital number, since it uses as much as digits as its factorization.

257638497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85879502.

The product of its digits is 2540160, while the sum is 51.

The square root of 257638497 is about 16051.1213626961. The cubic root of 257638497 is about 636.3122033304.

The spelling of 257638497 in words is "two hundred fifty-seven million, six hundred thirty-eight thousand, four hundred ninety-seven".