257725728 has 144 divisors (see below), whose sum is σ = 831055680. Its totient is φ = 75105792.

The previous prime is 257725711. The next prime is 257725759. The reversal of 257725728 is 827527752.

257725728 is a `hidden beast` number, since 2 + 5 + 7 + 72 + 572 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 69325 + ... + 72947.

It is an arithmetic number, because the mean of its divisors is an integer number (5771220).

Almost surely, 2^257725728 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 257725728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (415527840).

257725728 is an abundant number, since it is smaller than the sum of its proper divisors (573329952).

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

257725728 is a wasteful number, since it uses less digits than its factorization.

257725728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3671 (or 3660 counting only the distinct ones).

The product of its digits is 548800, while the sum is 45.

The square root of 257725728 is about 16053.8384195182. The cubic root of 257725728 is about 636.3840092228.

The spelling of 257725728 in words is "two hundred fifty-seven million, seven hundred twenty-five thousand, seven hundred twenty-eight".