161856928257 has 16 divisors (see below), whose sum is σ = 220425027840. Its totient is φ = 105597226112.

The previous prime is 161856928231. The next prime is 161856928297. The reversal of 161856928257 is 752829658161.

161856928257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 161856928257 - 2⁸ = 161856928001 is a prime.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 161856928257.

It is not an unprimeable number, because it can be changed into a prime (161856928297) 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 15 ways as a sum of consecutive naturals, for example, 1342183 + ... + 1457795.

It is an arithmetic number, because the mean of its divisors is an integer number (13776564240).

Almost surely, 2^161856928257 is an apocalyptic number.

It is an amenable number.

161856928257 is a deficient number, since it is larger than the sum of its proper divisors (58568099583).

161856928257 is a wasteful number, since it uses less digits than its factorization.

161856928257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125592.

The product of its digits is 14515200, while the sum is 60.

The spelling of 161856928257 in words is "one hundred sixty-one billion, eight hundred fifty-six million, nine hundred twenty-eight thousand, two hundred fifty-seven".