256817703403406 has 24 divisors (see below), whose sum is σ = 386791866036576. Its totient is φ = 127889162478720.

The previous prime is 256817703403403. The next prime is 256817703403423. The reversal of 256817703403406 is 604304307718652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256817703403403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 350592566 + ... + 351324326.

It is an arithmetic number, because the mean of its divisors is an integer number (16116327751524).

Almost surely, 2^{256817703403406} is an apocalyptic number.

256817703403406 is a deficient number, since it is larger than the sum of its proper divisors (129974162633170).

256817703403406 is an equidigital number, since it uses as much as digits as its factorization.

256817703403406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 734604 (or 734327 counting only the distinct ones).

The product of its (nonzero) digits is 20321280, while the sum is 56.

The spelling of 256817703403406 in words is "two hundred fifty-six trillion, eight hundred seventeen billion, seven hundred three million, four hundred three thousand, four hundred six".