256100025866 has 4 divisors (see below), whose sum is σ = 384150038802. Its totient is φ = 128050012932.

The previous prime is 256100025829. The next prime is 256100025893. The reversal of 256100025866 is 668520001652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 171052552225 + 85047473641 = 413585^2 + 291629^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64025006465 + ... + 64025006468.

Almost surely, 2^256100025866 is an apocalyptic number.

256100025866 is a deficient number, since it is larger than the sum of its proper divisors (128050012936).

256100025866 is a wasteful number, since it uses less digits than its factorization.

256100025866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128050012935.

The product of its (nonzero) digits is 172800, while the sum is 41.

The spelling of 256100025866 in words is "two hundred fifty-six billion, one hundred million, twenty-five thousand, eight hundred sixty-six".