256781634 has 16 divisors (see below), whose sum is σ = 543773088. Its totient is φ = 80558912.

The previous prime is 256781621. The next prime is 256781641. The reversal of 256781634 is 436187652.

256781634 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1258632 + ... + 1258835.

It is an arithmetic number, because the mean of its divisors is an integer number (33985818).

Almost surely, 2^256781634 is an apocalyptic number.

256781634 is an abundant number, since it is smaller than the sum of its proper divisors (286991454).

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

256781634 is a wasteful number, since it uses less digits than its factorization.

256781634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2517489.

The product of its digits is 241920, while the sum is 42.

The square root of 256781634 is about 16024.4074461429. The cubic root of 256781634 is about 635.6059968175.

The spelling of 256781634 in words is "two hundred fifty-six million, seven hundred eighty-one thousand, six hundred thirty-four".