256611805 has 8 divisors (see below), whose sum is σ = 321322752. Its totient is φ = 196363728.

The previous prime is 256611799. The next prime is 256611871. The reversal of 256611805 is 508116652.

It is a happy number.

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 256611805 - 2²¹ = 254514653 is a prime.

It is a Duffinian number.

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, 1115589 + ... + 1115818.

It is an arithmetic number, because the mean of its divisors is an integer number (40165344).

Almost surely, 2^256611805 is an apocalyptic number.

It is an amenable number.

256611805 is a deficient number, since it is larger than the sum of its proper divisors (64710947).

256611805 is a wasteful number, since it uses less digits than its factorization.

256611805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2231435.

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 256611805 is about 16019.1074969862. The cubic root of 256611805 is about 635.4658412372.

The spelling of 256611805 in words is "two hundred fifty-six million, six hundred eleven thousand, eight hundred five".