256661805353 has 8 divisors (see below), whose sum is σ = 262970136576. Its totient is φ = 250355773600.

The previous prime is 256661805343. The next prime is 256661805359. The reversal of 256661805353 is 353508166652.

256661805353 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.

It is a cyclic number.

It is not a de Polignac number, because 256661805353 - 2⁶ = 256661805289 is a prime.

It is a super-2 number, since 2×256661805353² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (256661805359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 347801 + ... + 796422.

It is an arithmetic number, because the mean of its divisors is an integer number (32871267072).

Almost surely, 2^256661805353 is an apocalyptic number.

It is an amenable number.

256661805353 is a deficient number, since it is larger than the sum of its proper divisors (6308331223).

256661805353 is a wasteful number, since it uses less digits than its factorization.

256661805353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1149735.

The product of its (nonzero) digits is 3888000, while the sum is 50.

The spelling of 256661805353 in words is "two hundred fifty-six billion, six hundred sixty-one million, eight hundred five thousand, three hundred fifty-three".