256428457 has 4 divisors (see below), whose sum is σ = 256461316. Its totient is φ = 256395600.

The previous prime is 256428437. The next prime is 256428467. The reversal of 256428457 is 754824652.

It is a happy number.

256428457 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 117094041 + 139334416 = 10821^2 + 11804^2 .

It is a cyclic number.

It is not a de Polignac number, because 256428457 - 2¹¹ = 256426409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256428407) 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, 2707 + ... + 22807.

It is an arithmetic number, because the mean of its divisors is an integer number (64115329).

Almost surely, 2^256428457 is an apocalyptic number.

It is an amenable number.

256428457 is a deficient number, since it is larger than the sum of its proper divisors (32859).

256428457 is a wasteful number, since it uses less digits than its factorization.

256428457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32858.

The product of its digits is 537600, while the sum is 43.

The square root of 256428457 is about 16013.3836836566. The cubic root of 256428457 is about 635.3144593330.

The spelling of 256428457 in words is "two hundred fifty-six million, four hundred twenty-eight thousand, four hundred fifty-seven".