256941978 has 64 divisors (see below), whose sum is σ = 576512640. Its totient is φ = 75866112.

The previous prime is 256941977. The next prime is 256942009. The reversal of 256941978 is 879149652.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 256941978.

It is not an unprimeable number, because it can be changed into a prime (256941977) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 381450 + ... + 382122.

It is an arithmetic number, because the mean of its divisors is an integer number (9008010).

Almost surely, 2^256941978 is an apocalyptic number.

256941978 is an abundant number, since it is smaller than the sum of its proper divisors (319570662).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256941978 is a wasteful number, since it uses less digits than its factorization.

256941978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 911.

The product of its digits is 1088640, while the sum is 51.

The square root of 256941978 is about 16029.4097832702. The cubic root of 256941978 is about 635.7382679622.

It can be divided in two parts, 25694 and 1978, that added together give a palindrome (27672).

The spelling of 256941978 in words is "two hundred fifty-six million, nine hundred forty-one thousand, nine hundred seventy-eight".