257566340 has 24 divisors (see below), whose sum is σ = 543143832. Its totient is φ = 102597120.

The previous prime is 257566333. The next prime is 257566343. The reversal of 257566340 is 43665752.

It can be written as a sum of positive squares in 4 ways, for example, as 63744256 + 193822084 = 7984^2 + 13922^2 .

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 257566294 and 257566303.

It is not an unprimeable number, because it can be changed into a prime (257566343) 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 7 ways as a sum of consecutive naturals, for example, 21899 + ... + 31538.

It is an arithmetic number, because the mean of its divisors is an integer number (22630993).

Almost surely, 2^257566340 is an apocalyptic number.

257566340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

257566340 is an abundant number, since it is smaller than the sum of its proper divisors (285577492).

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

257566340 is a wasteful number, since it uses less digits than its factorization.

257566340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53687 (or 53685 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 38.

The square root of 257566340 is about 16048.8734807151. The cubic root of 257566340 is about 636.2527936443.

The spelling of 257566340 in words is "two hundred fifty-seven million, five hundred sixty-six thousand, three hundred forty".