256615565 has 8 divisors (see below), whose sum is σ = 310364160. Its totient is φ = 203675472.

The previous prime is 256615547. The next prime is 256615589. The reversal of 256615565 is 565516652.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256615565 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 201425 + ... + 202694.

It is an arithmetic number, because the mean of its divisors is an integer number (38795520).

Almost surely, 2^256615565 is an apocalyptic number.

It is an amenable number.

256615565 is a deficient number, since it is larger than the sum of its proper divisors (53748595).

256615565 is a wasteful number, since it uses less digits than its factorization.

256615565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404251.

The product of its digits is 270000, while the sum is 41.

The square root of 256615565 is about 16019.2248564030. The cubic root of 256615565 is about 635.4689449394.

The spelling of 256615565 in words is "two hundred fifty-six million, six hundred fifteen thousand, five hundred sixty-five".