256777855 has 8 divisors (see below), whose sum is σ = 311184864. Its totient is φ = 203388000.

The previous prime is 256777849. The next prime is 256777889. The reversal of 256777855 is 558777652.

It is a happy number.

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

It is not a de Polignac number, because 256777855 - 2¹⁵ = 256745087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 253731 + ... + 254740.

It is an arithmetic number, because the mean of its divisors is an integer number (38898108).

Almost surely, 2^256777855 is an apocalyptic number.

256777855 is a deficient number, since it is larger than the sum of its proper divisors (54407009).

256777855 is a wasteful number, since it uses less digits than its factorization.

256777855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 508577.

The product of its digits is 4116000, while the sum is 52.

The square root of 256777855 is about 16024.2895318326. The cubic root of 256777855 is about 635.6028787767.

The spelling of 256777855 in words is "two hundred fifty-six million, seven hundred seventy-seven thousand, eight hundred fifty-five".