256539845 has 4 divisors (see below), whose sum is σ = 307847820. Its totient is φ = 205231872.

The previous prime is 256539841. The next prime is 256539923. The reversal of 256539845 is 548935652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 170903329 + 85636516 = 13073^2 + 9254^2 .

It is a cyclic number.

It is not a de Polignac number, because 256539845 - 2² = 256539841 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 256539845.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256539841) 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, 25653980 + ... + 25653989.

It is an arithmetic number, because the mean of its divisors is an integer number (76961955).

Almost surely, 2^256539845 is an apocalyptic number.

It is an amenable number.

256539845 is a deficient number, since it is larger than the sum of its proper divisors (51307975).

256539845 is an equidigital number, since it uses as much as digits as its factorization.

256539845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51307974.

The product of its digits is 1296000, while the sum is 47.

The square root of 256539845 is about 16016.8612717973. The cubic root of 256539845 is about 635.4064358160.

The spelling of 256539845 in words is "two hundred fifty-six million, five hundred thirty-nine thousand, eight hundred forty-five".