256869138 has 8 divisors (see below), whose sum is σ = 513738288. Its totient is φ = 85623044.

The previous prime is 256869097. The next prime is 256869169. The reversal of 256869138 is 831968652.

It is a happy number.

256869138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

256869138 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21405756 + ... + 21405767.

It is an arithmetic number, because the mean of its divisors is an integer number (64217286).

Almost surely, 2^256869138 is an apocalyptic number.

256869138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

256869138 is a wasteful number, since it uses less digits than its factorization.

256869138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42811528.

The product of its digits is 622080, while the sum is 48.

The square root of 256869138 is about 16027.1375485456. The cubic root of 256869138 is about 635.6781875343.

The spelling of 256869138 in words is "two hundred fifty-six million, eight hundred sixty-nine thousand, one hundred thirty-eight".