257385917 has 4 divisors (see below), whose sum is σ = 263371680. Its totient is φ = 251400156.

The previous prime is 257385889. The next prime is 257385923. The reversal of 257385917 is 719583752.

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 257385917 - 2⁶ = 257385853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257385977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2992817 + ... + 2992902.

It is an arithmetic number, because the mean of its divisors is an integer number (65842920).

Almost surely, 2^257385917 is an apocalyptic number.

It is an amenable number.

257385917 is a deficient number, since it is larger than the sum of its proper divisors (5985763).

257385917 is an equidigital number, since it uses as much as digits as its factorization.

257385917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5985762.

The product of its digits is 529200, while the sum is 47.

The square root of 257385917 is about 16043.2514472597. The cubic root of 257385917 is about 636.1041957433.

The spelling of 257385917 in words is "two hundred fifty-seven million, three hundred eighty-five thousand, nine hundred seventeen".