199969409 has 2 divisors, whose sum is σ = 199969410. Its totient is φ = 199969408.

The previous prime is 199969373. The next prime is 199969421. The reversal of 199969409 is 904969991.

199969409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165688384 + 34281025 = 12872^2 + 5855^2 .

It is an emirp because it is prime and its reverse (904969991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199969409 - 2¹² = 199965313 is a prime.

It is not a weakly prime, because it can be changed into another prime (199969439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99984704 + 99984705.

It is an arithmetic number, because the mean of its divisors is an integer number (99984705).

Almost surely, 2^199969409 is an apocalyptic number.

It is an amenable number.

199969409 is a deficient number, since it is larger than the sum of its proper divisors (1).

199969409 is an equidigital number, since it uses as much as digits as its factorization.

199969409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1417176, while the sum is 56.

The square root of 199969409 is about 14141.0540271933. The cubic root of 199969409 is about 584.7737299134.

The spelling of 199969409 in words is "one hundred ninety-nine million, nine hundred sixty-nine thousand, four hundred nine".