256456121 has 4 divisors (see below), whose sum is σ = 256992000. Its totient is φ = 255920244.

The previous prime is 256456103. The next prime is 256456133. The reversal of 256456121 is 121654652.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256456121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256456621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 267221 + ... + 268178.

It is an arithmetic number, because the mean of its divisors is an integer number (64248000).

Almost surely, 2^256456121 is an apocalyptic number.

It is an amenable number.

256456121 is a deficient number, since it is larger than the sum of its proper divisors (535879).

256456121 is an equidigital number, since it uses as much as digits as its factorization.

256456121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535878.

The product of its digits is 14400, while the sum is 32.

The square root of 256456121 is about 16014.2474378286. The cubic root of 256456121 is about 635.3373048307.

It can be divided in two parts, 2564 and 56121, that added together give a palindrome (58685).

The spelling of 256456121 in words is "two hundred fifty-six million, four hundred fifty-six thousand, one hundred twenty-one".