256564619 has 4 divisors (see below), whose sum is σ = 270068040. Its totient is φ = 243061200.

The previous prime is 256564603. The next prime is 256564631. The reversal of 256564619 is 916465652.

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

It is a cyclic number.

It is not a de Polignac number, because 256564619 - 2⁴ = 256564603 is a prime.

It is a super-2 number, since 2×256564619² = 131650807445230322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 256564619.

It is not an unprimeable number, because it can be changed into a prime (256564639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6751682 + ... + 6751719.

It is an arithmetic number, because the mean of its divisors is an integer number (67517010).

Almost surely, 2^256564619 is an apocalyptic number.

256564619 is a deficient number, since it is larger than the sum of its proper divisors (13503421).

256564619 is a wasteful number, since it uses less digits than its factorization.

256564619 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13503420.

The product of its digits is 388800, while the sum is 44.

The square root of 256564619 is about 16017.6346256243. The cubic root of 256564619 is about 635.4268888472.

The spelling of 256564619 in words is "two hundred fifty-six million, five hundred sixty-four thousand, six hundred nineteen".