257393440 has 96 divisors (see below), whose sum is σ = 627056640. Its totient is φ = 99800064.

The previous prime is 257393419. The next prime is 257393443. The reversal of 257393440 is 44393752.

It is a self number, because there is not a number n which added to its sum of digits gives 257393440.

It is not an unprimeable number, because it can be changed into a prime (257393443) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1076841 + ... + 1077079.

It is an arithmetic number, because the mean of its divisors is an integer number (6531840).

Almost surely, 2^257393440 is an apocalyptic number.

257393440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257393440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (313528320).

257393440 is an abundant number, since it is smaller than the sum of its proper divisors (369663200).

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

257393440 is a wasteful number, since it uses less digits than its factorization.

257393440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434 (or 426 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 37.

The square root of 257393440 is about 16043.4859055007. The cubic root of 257393440 is about 636.1103931366.

The spelling of 257393440 in words is "two hundred fifty-seven million, three hundred ninety-three thousand, four hundred forty".