256191409926 has 64 divisors (see below), whose sum is σ = 575500723200. Its totient is φ = 84471069888.

The previous prime is 256191409889. The next prime is 256191409931. The reversal of 256191409926 is 629904191652.

256191409926 is a `hidden beast` number, since 2 + 5 + 61 + 91 + 409 + 92 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4907530 + ... + 4959458.

It is an arithmetic number, because the mean of its divisors is an integer number (8992198800).

Almost surely, 2^256191409926 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256191409926, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (287750361600).

256191409926 is an abundant number, since it is smaller than the sum of its proper divisors (319309313274).

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

256191409926 is a wasteful number, since it uses less digits than its factorization.

256191409926 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52930 (or 52924 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 54.

The spelling of 256191409926 in words is "two hundred fifty-six billion, one hundred ninety-one million, four hundred nine thousand, nine hundred twenty-six".