256778805 has 8 divisors (see below), whose sum is σ = 410846112. Its totient is φ = 136948688.

The previous prime is 256778803. The next prime is 256778807. The reversal of 256778805 is 508877652.

256778805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (256778803) and next prime (256778807).

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 256778805 - 2¹ = 256778803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256778803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8559279 + ... + 8559308.

It is an arithmetic number, because the mean of its divisors is an integer number (51355764).

Almost surely, 2^256778805 is an apocalyptic number.

It is an amenable number.

256778805 is a deficient number, since it is larger than the sum of its proper divisors (154067307).

256778805 is a wasteful number, since it uses less digits than its factorization.

256778805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17118595.

The product of its (nonzero) digits is 940800, while the sum is 48.

The square root of 256778805 is about 16024.3191743050. The cubic root of 256778805 is about 635.6036626215.

The spelling of 256778805 in words is "two hundred fifty-six million, seven hundred seventy-eight thousand, eight hundred five".