257218049864 has 16 divisors (see below), whose sum is σ = 486551843820. Its totient is φ = 127470891520.

The previous prime is 257218049863. The next prime is 257218049903. The reversal of 257218049864 is 468940812752.

It can be written as a sum of positive squares in 2 ways, for example, as 243019420900 + 14198628964 = 492970^2 + 119158^2 .

It is a super-2 number, since 2×257218049864² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (257218049863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142265717 + ... + 142267524.

Almost surely, 2^257218049864 is an apocalyptic number.

It is an amenable number.

257218049864 is a deficient number, since it is larger than the sum of its proper divisors (229333793956).

257218049864 is a wasteful number, since it uses less digits than its factorization.

257218049864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284533360 (or 284533356 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 56.

The spelling of 257218049864 in words is "two hundred fifty-seven billion, two hundred eighteen million, forty-nine thousand, eight hundred sixty-four".