186805121 has 4 divisors (see below), whose sum is σ = 186832644. Its totient is φ = 186777600.

The previous prime is 186805111. The next prime is 186805133. The reversal of 186805121 is 121508681.

186805121 = 9664² + 9665².

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 93392896 + 93412225 = 9664^2 + 9665^2 .

It is a cyclic number.

It is not a de Polignac number, because 186805121 - 2¹⁰ = 186804097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (186805111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4481 + ... + 19841.

It is an arithmetic number, because the mean of its divisors is an integer number (46708161).

Almost surely, 2^186805121 is an apocalyptic number.

186805121 is the 9665-th centered square number.

It is an amenable number.

186805121 is a deficient number, since it is larger than the sum of its proper divisors (27523).

186805121 is a wasteful number, since it uses less digits than its factorization.

186805121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27522.

The product of its (nonzero) digits is 3840, while the sum is 32.

The square root of 186805121 is about 13667.6669918461. Note that the first 3 decimals coincide. The cubic root of 186805121 is about 571.6491901185.

The spelling of 186805121 in words is "one hundred eighty-six million, eight hundred five thousand, one hundred twenty-one".