256105121 has 8 divisors (see below), whose sum is σ = 258745344. Its totient is φ = 253471680.

The previous prime is 256105099. The next prime is 256105139. The reversal of 256105121 is 121501652.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256105121 - 2²⁶ = 188996257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256105141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110840 + ... + 113126.

It is an arithmetic number, because the mean of its divisors is an integer number (32343168).

Almost surely, 2^256105121 is an apocalyptic number.

It is an amenable number.

256105121 is a deficient number, since it is larger than the sum of its proper divisors (2640223).

256105121 is a wasteful number, since it uses less digits than its factorization.

256105121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3391.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 256105121 is about 16003.2846940870. The cubic root of 256105121 is about 635.0473199283.

Adding to 256105121 its reverse (121501652), we get a palindrome (377606773).

The spelling of 256105121 in words is "two hundred fifty-six million, one hundred five thousand, one hundred twenty-one".