256641778 has 16 divisors (see below), whose sum is σ = 405720000. Its totient is φ = 121418352.

The previous prime is 256641773. The next prime is 256641779. The reversal of 256641778 is 877146652.

It is a happy number.

256641778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (256641773) 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, 31248 + ... + 38596.

It is an arithmetic number, because the mean of its divisors is an integer number (25357500).

Almost surely, 2^256641778 is an apocalyptic number.

256641778 is a deficient number, since it is larger than the sum of its proper divisors (149078222).

256641778 is a wasteful number, since it uses less digits than its factorization.

256641778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8289.

The product of its digits is 564480, while the sum is 46.

The square root of 256641778 is about 16020.0430086813. The cubic root of 256641778 is about 635.4905816892.

It can be divided in two parts, 2566 and 41778, that added together give a palindrome (44344).

The spelling of 256641778 in words is "two hundred fifty-six million, six hundred forty-one thousand, seven hundred seventy-eight".