165644686446561 has 96 divisors (see below), whose sum is σ = 279455174668800. Its totient is φ = 92600202240000.

The previous prime is 165644686446539. The next prime is 165644686446587.

165644686446561 is a `hidden beast` number, since 1 + 6 + 5 + 6 + 4 + 46 + 8 + 64 + 465 + 61 = 666.

165644686446561 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 165644686446561 - 2⁶ = 165644686446497 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165644686446561.

It is not an unprimeable number, because it can be changed into a prime (165644686446661) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 293988211 + ... + 294551111.

It is an arithmetic number, because the mean of its divisors is an integer number (2910991402800).

Almost surely, 2^{165644686446561} is an apocalyptic number.

It is an amenable number.

165644686446561 is a deficient number, since it is larger than the sum of its proper divisors (113810488222239).

165644686446561 is a wasteful number, since it uses less digits than its factorization.

165644686446561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 563567 (or 563564 counting only the distinct ones).

The product of its digits is 2388787200, while the sum is 72.

The spelling of 165644686446561 in words is "one hundred sixty-five trillion, six hundred forty-four billion, six hundred eighty-six million, four hundred forty-six thousand, five hundred sixty-one".