257504405 has 4 divisors (see below), whose sum is σ = 309005292. Its totient is φ = 206003520.

The previous prime is 257504393. The next prime is 257504407. The reversal of 257504405 is 504405752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 123454321 + 134050084 = 11111^2 + 11578^2 .

It is not a de Polignac number, because 257504405 - 2¹⁶ = 257438869 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 (257504407) 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, 25750436 + ... + 25750445.

It is an arithmetic number, because the mean of its divisors is an integer number (77251323).

Almost surely, 2^257504405 is an apocalyptic number.

It is an amenable number.

257504405 is a deficient number, since it is larger than the sum of its proper divisors (51500887).

257504405 is an equidigital number, since it uses as much as digits as its factorization.

257504405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51500886.

The product of its (nonzero) digits is 28000, while the sum is 32.

The square root of 257504405 is about 16046.9437900181. The cubic root of 257504405 is about 636.2017912815.

The spelling of 257504405 in words is "two hundred fifty-seven million, five hundred four thousand, four hundred five".