257685864 has 32 divisors (see below), whose sum is σ = 682110720. Its totient is φ = 80842496.

The previous prime is 257685829. The next prime is 257685889. The reversal of 257685864 is 468586752.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 315384 + ... + 316199.

It is an arithmetic number, because the mean of its divisors is an integer number (21315960).

Almost surely, 2^257685864 is an apocalyptic number.

257685864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

257685864 is an abundant number, since it is smaller than the sum of its proper divisors (424424856).

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

257685864 is a wasteful number, since it uses less digits than its factorization.

257685864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631609 (or 631605 counting only the distinct ones).

The product of its digits is 3225600, while the sum is 51.

The square root of 257685864 is about 16052.5967992721. The cubic root of 257685864 is about 636.3511964074.

The spelling of 257685864 in words is "two hundred fifty-seven million, six hundred eighty-five thousand, eight hundred sixty-four".