257928389 has 4 divisors (see below), whose sum is σ = 259897440. Its totient is φ = 255959340.

The previous prime is 257928383. The next prime is 257928397. The reversal of 257928389 is 983829752.

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 257928389 - 2⁸ = 257928133 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 257928389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257928383) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 984329 + ... + 984590.

It is an arithmetic number, because the mean of its divisors is an integer number (64974360).

Almost surely, 2^257928389 is an apocalyptic number.

It is an amenable number.

257928389 is a deficient number, since it is larger than the sum of its proper divisors (1969051).

257928389 is a wasteful number, since it uses less digits than its factorization.

257928389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1969050.

The product of its digits is 2177280, while the sum is 53.

The square root of 257928389 is about 16060.1490964437. The cubic root of 257928389 is about 636.5507710365.

The spelling of 257928389 in words is "two hundred fifty-seven million, nine hundred twenty-eight thousand, three hundred eighty-nine".