186561856121 has 16 divisors (see below), whose sum is σ = 203929743360. Its totient is φ = 170017140240.

The previous prime is 186561856097. The next prime is 186561856133. The reversal of 186561856121 is 121658165681.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-186561856121 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 186561856121.

It is not an unprimeable number, because it can be changed into a prime (186561856141) 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, 849971 + ... + 1046696.

It is an arithmetic number, because the mean of its divisors is an integer number (12745608960).

Almost surely, 2^186561856121 is an apocalyptic number.

It is an amenable number.

186561856121 is a deficient number, since it is larger than the sum of its proper divisors (17367887239).

186561856121 is a wasteful number, since it uses less digits than its factorization.

186561856121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1896884.

The product of its digits is 691200, while the sum is 50.

The spelling of 186561856121 in words is "one hundred eighty-six billion, five hundred sixty-one million, eight hundred fifty-six thousand, one hundred twenty-one".