190491221209 has 9 divisors (see below), whose sum is σ = 192335303797. Its totient is φ = 188664665404.

The previous prime is 190491221203. The next prime is 190491221251. The reversal of 190491221209 is 902122194091.

The square root of 190491221209 is 436453.

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

190491221209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 190491221209 - 2⁵ = 190491221177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (190491221203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 46698432 + ... + 46702510.

Almost surely, 2^190491221209 is an apocalyptic number.

190491221209 is the 436453-rd square number.

190491221209 is the 218227-th centered octagonal number.

It is an amenable number.

190491221209 is a deficient number, since it is larger than the sum of its proper divisors (1844082588).

190491221209 is an frugal number, since it uses more digits than its factorization.

190491221209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8372 (or 4186 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 40.

The spelling of 190491221209 in words is "one hundred ninety billion, four hundred ninety-one million, two hundred twenty-one thousand, two hundred nine".