257731328 has 54 divisors (see below), whose sum is σ = 524672316. Its totient is φ = 126345216.

The previous prime is 257731277. The next prime is 257731343. The reversal of 257731328 is 823137752.

It is a junction number, because it is equal to n+sod(n) for n = 257731291 and 257731300.

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 5 ways as a sum of consecutive naturals, for example, 2408651 + ... + 2408757.

It is an arithmetic number, because the mean of its divisors is an integer number (9716154).

Almost surely, 2^257731328 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 257731328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262336158).

257731328 is an abundant number, since it is smaller than the sum of its proper divisors (266940988).

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

257731328 is an frugal number, since it uses more digits than its factorization.

257731328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317 (or 206 counting only the distinct ones).

The product of its digits is 70560, while the sum is 38.

The square root of 257731328 is about 16054.0128316879. The cubic root of 257731328 is about 636.3886184181.

The spelling of 257731328 in words is "two hundred fifty-seven million, seven hundred thirty-one thousand, three hundred twenty-eight".