199185521 has 2 divisors, whose sum is σ = 199185522. Its totient is φ = 199185520.

The previous prime is 199185487. The next prime is 199185551. The reversal of 199185521 is 125581991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 134560000 + 64625521 = 11600^2 + 8039^2 .

It is a cyclic number.

It is not a de Polignac number, because 199185521 - 2¹⁰ = 199184497 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199185551) 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 as a sum of consecutive naturals, namely, 99592760 + 99592761.

It is an arithmetic number, because the mean of its divisors is an integer number (99592761).

Almost surely, 2^199185521 is an apocalyptic number.

It is an amenable number.

199185521 is a deficient number, since it is larger than the sum of its proper divisors (1).

199185521 is an equidigital number, since it uses as much as digits as its factorization.

199185521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32400, while the sum is 41.

The square root of 199185521 is about 14113.3100653249. The cubic root of 199185521 is about 584.0086172260.

The spelling of 199185521 in words is "one hundred ninety-nine million, one hundred eighty-five thousand, five hundred twenty-one".