257556864 has 64 divisors (see below), whose sum is σ = 688267440. Its totient is φ = 85334016.

The previous prime is 257556841. The next prime is 257556869. The reversal of 257556864 is 468655752.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257556869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64494 + ... + 68370.

Almost surely, 2^257556864 is an apocalyptic number.

257556864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257556864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (344133720).

257556864 is an abundant number, since it is smaller than the sum of its proper divisors (430710576).

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

257556864 is a wasteful number, since it uses less digits than its factorization.

257556864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4067 (or 4055 counting only the distinct ones).

The product of its digits is 2016000, while the sum is 48.

The square root of 257556864 is about 16048.5782547863. The cubic root of 257556864 is about 636.2449908579.

The spelling of 257556864 in words is "two hundred fifty-seven million, five hundred fifty-six thousand, eight hundred sixty-four".