199180621790209 has 4 divisors (see below), whose sum is σ = 199180691768916. Its totient is φ = 199180551811504.

The previous prime is 199180621790099. The next prime is 199180621790309. The reversal of 199180621790209 is 902097126081991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 198310384681984 + 870237108225 = 14082272^2 + 932865^2 .

It is a cyclic number.

It is not a de Polignac number, because 199180621790209 - 2¹⁷ = 199180621659137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199180621790309) 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, 30530494 + ... + 36475639.

It is an arithmetic number, because the mean of its divisors is an integer number (49795172942229).

Almost surely, 2^{199180621790209} is an apocalyptic number.

It is an amenable number.

199180621790209 is a deficient number, since it is larger than the sum of its proper divisors (69978707).

199180621790209 is an equidigital number, since it uses as much as digits as its factorization.

199180621790209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69978706.

The product of its (nonzero) digits is 8817984, while the sum is 64.

The spelling of 199180621790209 in words is "one hundred ninety-nine trillion, one hundred eighty billion, six hundred twenty-one million, seven hundred ninety thousand, two hundred nine".