257242205865 has 16 divisors (see below), whose sum is σ = 411737754816. Its totient is φ = 137145768000.

The previous prime is 257242205861. The next prime is 257242205867. The reversal of 257242205865 is 568502242752.

It is not a de Polignac number, because 257242205865 - 2² = 257242205861 is a prime.

It is not an unprimeable number, because it can be changed into a prime (257242205861) 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, 3087211 + ... + 3169440.

It is an arithmetic number, because the mean of its divisors is an integer number (25733609676).

Almost surely, 2^257242205865 is an apocalyptic number.

It is an amenable number.

257242205865 is a deficient number, since it is larger than the sum of its proper divisors (154495548951).

257242205865 is a wasteful number, since it uses less digits than its factorization.

257242205865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6259400.

The product of its (nonzero) digits is 2688000, while the sum is 48.

The spelling of 257242205865 in words is "two hundred fifty-seven billion, two hundred forty-two million, two hundred five thousand, eight hundred sixty-five".