257408865 has 96 divisors (see below), whose sum is σ = 550368000. Its totient is φ = 108656640.

The previous prime is 257408861. The next prime is 257408897. The reversal of 257408865 is 568804752.

It is not a de Polignac number, because 257408865 - 2² = 257408861 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 257408865.

It is not an unprimeable number, because it can be changed into a prime (257408861) 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 95 ways as a sum of consecutive naturals, for example, 244861 + ... + 245909.

It is an arithmetic number, because the mean of its divisors is an integer number (5733000).

Almost surely, 2^257408865 is an apocalyptic number.

It is an amenable number.

257408865 is an abundant number, since it is smaller than the sum of its proper divisors (292959135).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

257408865 is a wasteful number, since it uses less digits than its factorization.

257408865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1127 (or 1124 counting only the distinct ones).

The product of its (nonzero) digits is 537600, while the sum is 45.

The square root of 257408865 is about 16043.9666230019. The cubic root of 257408865 is about 636.1230997630.

The spelling of 257408865 in words is "two hundred fifty-seven million, four hundred eight thousand, eight hundred sixty-five".