257640028 has 12 divisors (see below), whose sum is σ = 463055992. Its totient is φ = 125338320.

The previous prime is 257640017. The next prime is 257640029. The reversal of 257640028 is 820046752.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 257639975 and 257640002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257640029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 870258 + ... + 870553.

Almost surely, 2^257640028 is an apocalyptic number.

It is an amenable number.

257640028 is a deficient number, since it is larger than the sum of its proper divisors (205415964).

257640028 is a wasteful number, since it uses less digits than its factorization.

257640028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1740852 (or 1740850 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 34.

The square root of 257640028 is about 16051.1690539973. The cubic root of 257640028 is about 636.3134637426.

The spelling of 257640028 in words is "two hundred fifty-seven million, six hundred forty thousand, twenty-eight".