256641365 has 8 divisors (see below), whose sum is σ = 308725080. Its totient is φ = 204809472.

The previous prime is 256641349. The next prime is 256641373. The reversal of 256641365 is 563146652.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 102434641 + 154206724 = 10121^2 + 12418^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256641365 - 2⁴ = 256641349 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60704 + ... + 64793.

It is an arithmetic number, because the mean of its divisors is an integer number (38590635).

Almost surely, 2^256641365 is an apocalyptic number.

It is an amenable number.

256641365 is a deficient number, since it is larger than the sum of its proper divisors (52083715).

256641365 is a wasteful number, since it uses less digits than its factorization.

256641365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125911.

The product of its digits is 129600, while the sum is 38.

The square root of 256641365 is about 16020.0301185734. The cubic root of 256641365 is about 635.4902408019.

The spelling of 256641365 in words is "two hundred fifty-six million, six hundred forty-one thousand, three hundred sixty-five".