195212609 has 2 divisors, whose sum is σ = 195212610. Its totient is φ = 195212608.

The previous prime is 195212599. The next prime is 195212617. The reversal of 195212609 is 906212591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 125440000 + 69772609 = 11200^2 + 8353^2 .

It is a cyclic number.

It is not a de Polignac number, because 195212609 - 2¹² = 195208513 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (195215609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97606304 + 97606305.

It is an arithmetic number, because the mean of its divisors is an integer number (97606305).

Almost surely, 2^195212609 is an apocalyptic number.

It is an amenable number.

195212609 is a deficient number, since it is larger than the sum of its proper divisors (1).

195212609 is an equidigital number, since it uses as much as digits as its factorization.

195212609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 195212609 is about 13971.8505932464. The cubic root of 195212609 is about 580.0996747047.

The spelling of 195212609 in words is "one hundred ninety-five million, two hundred twelve thousand, six hundred nine".