161556655161 has 16 divisors (see below), whose sum is σ = 235019245248. Its totient is φ = 97901563200.

The previous prime is 161556655157. The next prime is 161556655171.

161556655161 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 161556655161 - 2² = 161556655157 is a prime.

It is a super-2 number, since 2×161556655161² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161556655161.

It is not an unprimeable number, because it can be changed into a prime (161556655151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1030 + ... + 568431.

It is an arithmetic number, because the mean of its divisors is an integer number (14688702828).

Almost surely, 2^161556655161 is an apocalyptic number.

161556655161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161556655161 is a deficient number, since it is larger than the sum of its proper divisors (73462590087).

161556655161 is a wasteful number, since it uses less digits than its factorization.

161556655161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578072.

The product of its digits is 810000, while the sum is 48.

The spelling of 161556655161 in words is "one hundred sixty-one billion, five hundred fifty-six million, six hundred fifty-five thousand, one hundred sixty-one".