188502720561 has 45 divisors (see below), whose sum is σ = 297308161161. Its totient is φ = 119007459576.

The previous prime is 188502720533. The next prime is 188502720569. The reversal of 188502720561 is 165027205881.

The square root of 188502720561 is 434169.

It is a perfect power (a square), and thus also a powerful number.

188502720561 is a `hidden beast` number, since 1 + 8 + 85 + 0 + 2 + 7 + 2 + 0 + 561 = 666.

It is not a de Polignac number, because 188502720561 - 2⁷ = 188502720433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (188502720569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 74241630 + ... + 74244168.

Almost surely, 2^188502720561 is an apocalyptic number.

188502720561 is the 434169-th square number.

188502720561 is the 217085-th centered octagonal number.

It is an amenable number.

188502720561 is a deficient number, since it is larger than the sum of its proper divisors (108805440600).

188502720561 is an frugal number, since it uses more digits than its factorization.

188502720561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5128 (or 2561 counting only the distinct ones).

The product of its (nonzero) digits is 268800, while the sum is 45.

The spelling of 188502720561 in words is "one hundred eighty-eight billion, five hundred two million, seven hundred twenty thousand, five hundred sixty-one".