257998817 has 8 divisors (see below), whose sum is σ = 280559016. Its totient is φ = 236259072.

The previous prime is 257998759. The next prime is 257998823. The reversal of 257998817 is 718899752.

It can be written as a sum of positive squares in 4 ways, for example, as 65788321 + 192210496 = 8111^2 + 13864^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 257998817 - 2⁸ = 257998561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (257998837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 204458 + ... + 205715.

It is an arithmetic number, because the mean of its divisors is an integer number (35069877).

Almost surely, 2^257998817 is an apocalyptic number.

It is an amenable number.

257998817 is a deficient number, since it is larger than the sum of its proper divisors (22560199).

257998817 is a wasteful number, since it uses less digits than its factorization.

257998817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410227.

The product of its digits is 2540160, while the sum is 56.

The square root of 257998817 is about 16062.3415789853. The cubic root of 257998817 is about 636.6087030308.

The spelling of 257998817 in words is "two hundred fifty-seven million, nine hundred ninety-eight thousand, eight hundred seventeen".