256305566405 has 48 divisors (see below), whose sum is σ = 368237736576. Its totient is φ = 170690002560.

The previous prime is 256305566383. The next prime is 256305566411. The reversal of 256305566405 is 504665503652.

It is not a de Polignac number, because 256305566405 - 2¹⁴ = 256305550021 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256305566405.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1055507 + ... + 1275423.

It is an arithmetic number, because the mean of its divisors is an integer number (7671619512).

Almost surely, 2^256305566405 is an apocalyptic number.

It is an amenable number.

256305566405 is a deficient number, since it is larger than the sum of its proper divisors (111932170171).

256305566405 is a wasteful number, since it uses less digits than its factorization.

256305566405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220074 (or 220067 counting only the distinct ones).

The product of its (nonzero) digits is 3240000, while the sum is 47.

The spelling of 256305566405 in words is "two hundred fifty-six billion, three hundred five million, five hundred sixty-six thousand, four hundred five".