257645728 has 48 divisors (see below), whose sum is σ = 523200384. Its totient is φ = 124825600.

The previous prime is 257645711. The next prime is 257645749. The reversal of 257645728 is 827546752.

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, 160128 + ... + 161728.

It is an arithmetic number, because the mean of its divisors is an integer number (10900008).

Almost surely, 2^257645728 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 257645728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261600192).

257645728 is an abundant number, since it is smaller than the sum of its proper divisors (265554656).

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

257645728 is a wasteful number, since it uses less digits than its factorization.

257645728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1765 (or 1757 counting only the distinct ones).

The product of its digits is 940800, while the sum is 46.

The square root of 257645728 is about 16051.3466101757. The cubic root of 257645728 is about 636.3181562846.

The spelling of 257645728 in words is "two hundred fifty-seven million, six hundred forty-five thousand, seven hundred twenty-eight".