257705409 has 16 divisors (see below), whose sum is σ = 386128512. Its totient is φ = 151692288.

The previous prime is 257705389. The next prime is 257705423. The reversal of 257705409 is 904507752.

257705409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 257705409 - 2⁸ = 257705153 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (257705309) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142752 + ... + 144545.

It is an arithmetic number, because the mean of its divisors is an integer number (24133032).

Almost surely, 2^257705409 is an apocalyptic number.

It is an amenable number.

257705409 is a deficient number, since it is larger than the sum of its proper divisors (128423103).

257705409 is a wasteful number, since it uses less digits than its factorization.

257705409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287336.

The product of its (nonzero) digits is 88200, while the sum is 39.

The square root of 257705409 is about 16053.2055677363. The cubic root of 257705409 is about 636.3672846909.

The spelling of 257705409 in words is "two hundred fifty-seven million, seven hundred five thousand, four hundred nine".