256438743590 has 32 divisors (see below), whose sum is σ = 468416369664. Its totient is φ = 101060477280.

The previous prime is 256438743581. The next prime is 256438743619. The reversal of 256438743590 is 95347834652.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 902567 + ... + 1152173.

It is an arithmetic number, because the mean of its divisors is an integer number (14638011552).

Almost surely, 2^256438743590 is an apocalyptic number.

256438743590 is a deficient number, since it is larger than the sum of its proper divisors (211977626074).

256438743590 is a wasteful number, since it uses less digits than its factorization.

256438743590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251132.

The product of its (nonzero) digits is 21772800, while the sum is 56.

The spelling of 256438743590 in words is "two hundred fifty-six billion, four hundred thirty-eight million, seven hundred forty-three thousand, five hundred ninety".