256123978 has 16 divisors (see below), whose sum is σ = 419398560. Its totient is φ = 116340400.

The previous prime is 256123951. The next prime is 256123979. The reversal of 256123978 is 879321652.

It is not an unprimeable number, because it can be changed into a prime (256123979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39468 + ... + 45496.

It is an arithmetic number, because the mean of its divisors is an integer number (26212410).

Almost surely, 2^256123978 is an apocalyptic number.

256123978 is a deficient number, since it is larger than the sum of its proper divisors (163274582).

256123978 is a wasteful number, since it uses less digits than its factorization.

256123978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7973.

The product of its digits is 181440, while the sum is 43.

The square root of 256123978 is about 16003.8738435418. The cubic root of 256123978 is about 635.0629057073.

The spelling of 256123978 in words is "two hundred fifty-six million, one hundred twenty-three thousand, nine hundred seventy-eight".