256769856 has 168 divisors, whose sum is σ = 861267264. Its totient is φ = 71608320.

The previous prime is 256769837. The next prime is 256769873. The reversal of 256769856 is 658967652.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (168).

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 172636 + ... + 174116.

Almost surely, 2^256769856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256769856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (430633632).

256769856 is an abundant number, since it is smaller than the sum of its proper divisors (604497408).

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

256769856 is a wasteful number, since it uses less digits than its factorization.

256769856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1549 (or 1536 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 54.

The square root of 256769856 is about 16024.0399400401. The cubic root of 256769856 is about 635.5962787265.

The spelling of 256769856 in words is "two hundred fifty-six million, seven hundred sixty-nine thousand, eight hundred fifty-six".