256705250121 has 24 divisors (see below), whose sum is σ = 381581408000. Its totient is φ = 166177715616.

The previous prime is 256705250111. The next prime is 256705250147. The reversal of 256705250121 is 121052507652.

256705250121 is a `hidden beast` number, since 2 + 5 + 6 + 7 + 0 + 525 + 0 + 121 = 666.

256705250121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256705250121 - 2¹⁷ = 256705119049 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256705250111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 606265 + ... + 938598.

Almost surely, 2^256705250121 is an apocalyptic number.

It is an amenable number.

256705250121 is a deficient number, since it is larger than the sum of its proper divisors (124876157879).

256705250121 is a wasteful number, since it uses less digits than its factorization.

256705250121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1545405 (or 1545402 counting only the distinct ones).

The product of its (nonzero) digits is 42000, while the sum is 36.

Adding to 256705250121 its reverse (121052507652), we get a palindrome (377757757773).

The spelling of 256705250121 in words is "two hundred fifty-six billion, seven hundred five million, two hundred fifty thousand, one hundred twenty-one".