257405988 has 48 divisors (see below), whose sum is σ = 688472064. Its totient is φ = 73324320.

The previous prime is 257405987. The next prime is 257405999. The reversal of 257405988 is 889504752.

It is a super-2 number, since 2×257405988² = 132515685316512288, which contains 22 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (257405987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24733 + ... + 33563.

It is an arithmetic number, because the mean of its divisors is an integer number (14343168).

Almost surely, 2^257405988 is an apocalyptic number.

257405988 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

257405988 is an abundant number, since it is smaller than the sum of its proper divisors (431066076).

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

257405988 is a wasteful number, since it uses less digits than its factorization.

257405988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9192 (or 9190 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 48.

The square root of 257405988 is about 16043.8769628790. The cubic root of 257405988 is about 636.1207298200.

The spelling of 257405988 in words is "two hundred fifty-seven million, four hundred five thousand, nine hundred eighty-eight".