161556690411 has 12 divisors (see below), whose sum is σ = 241406549280. Its totient is φ = 103990513200.

The previous prime is 161556690409. The next prime is 161556690419. The reversal of 161556690411 is 114096655161.

161556690411 is a `hidden beast` number, since 1 + 6 + 1 + 556 + 6 + 90 + 4 + 1 + 1 = 666.

It is not a de Polignac number, because 161556690411 - 2¹ = 161556690409 is a prime.

It is a super-2 number, since 2×161556690411² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161556690419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 309495315 + ... + 309495836.

It is an arithmetic number, because the mean of its divisors is an integer number (20117212440).

Almost surely, 2^161556690411 is an apocalyptic number.

161556690411 is a deficient number, since it is larger than the sum of its proper divisors (79849858869).

161556690411 is a wasteful number, since it uses less digits than its factorization.

161556690411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 618991186 (or 618991183 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 45.

The spelling of 161556690411 in words is "one hundred sixty-one billion, five hundred fifty-six million, six hundred ninety thousand, four hundred eleven".