257663856 has 80 divisors (see below), whose sum is σ = 695491200. Its totient is φ = 82116864.

The previous prime is 257663851. The next prime is 257663867. The reversal of 257663856 is 658366752.

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 (257663851) 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, 103555 + ... + 106013.

It is an arithmetic number, because the mean of its divisors is an integer number (8693640).

Almost surely, 2^257663856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257663856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (347745600).

257663856 is an abundant number, since it is smaller than the sum of its proper divisors (437827344).

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

257663856 is a wasteful number, since it uses less digits than its factorization.

257663856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2566 (or 2560 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 48.

The square root of 257663856 is about 16051.9112880678. The cubic root of 257663856 is about 636.3330797548. Note that the first 3 decimals are identical.

The spelling of 257663856 in words is "two hundred fifty-seven million, six hundred sixty-three thousand, eight hundred fifty-six".