256121234455 has 16 divisors (see below), whose sum is σ = 317341476864. Its totient is φ = 198236391840.

The previous prime is 256121234407. The next prime is 256121234483. The reversal of 256121234455 is 554432121652.

It is not a de Polignac number, because 256121234455 - 2³³ = 247531299863 is a prime.

It is a Duffinian 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, 397462 + ... + 818668.

It is an arithmetic number, because the mean of its divisors is an integer number (19833842304).

Almost surely, 2^256121234455 is an apocalyptic number.

256121234455 is a deficient number, since it is larger than the sum of its proper divisors (61220242409).

256121234455 is a wasteful number, since it uses less digits than its factorization.

256121234455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425166.

The product of its digits is 288000, while the sum is 40.

The spelling of 256121234455 in words is "two hundred fifty-six billion, one hundred twenty-one million, two hundred thirty-four thousand, four hundred fifty-five".