257828640 has 48 divisors (see below), whose sum is σ = 812161728. Its totient is φ = 68754176.

The previous prime is 257828629. The next prime is 257828653. The reversal of 257828640 is 46828752.

It is a happy number.

257828640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 257828592 and 257828601.

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, 268092 + ... + 269051.

It is an arithmetic number, because the mean of its divisors is an integer number (16920036).

Almost surely, 2^257828640 is an apocalyptic number.

257828640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

257828640 is an abundant number, since it is smaller than the sum of its proper divisors (554333088).

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

257828640 is a wasteful number, since it uses less digits than its factorization.

257828640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537161 (or 537153 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 42.

The square root of 257828640 is about 16057.0433143839. The cubic root of 257828640 is about 636.4687024049.

The spelling of 257828640 in words is "two hundred fifty-seven million, eight hundred twenty-eight thousand, six hundred forty".