256636564 has 6 divisors (see below), whose sum is σ = 449113994. Its totient is φ = 128318280.

The previous prime is 256636559. The next prime is 256636571. The reversal of 256636564 is 465636652.

It can be written as a sum of positive squares in only one way, i.e., 253064464 + 3572100 = 15908^2 + 1890^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 256636564.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 32079567 + ... + 32079574.

Almost surely, 2^256636564 is an apocalyptic number.

It is an amenable number.

256636564 is a deficient number, since it is larger than the sum of its proper divisors (192477430).

256636564 is a wasteful number, since it uses less digits than its factorization.

256636564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64159145 (or 64159143 counting only the distinct ones).

The product of its digits is 777600, while the sum is 43.

The square root of 256636564 is about 16019.8802742093. The cubic root of 256636564 is about 635.4862780636.

The spelling of 256636564 in words is "two hundred fifty-six million, six hundred thirty-six thousand, five hundred sixty-four".