195644381909 has 2 divisors, whose sum is σ = 195644381910. Its totient is φ = 195644381908.

The previous prime is 195644381887. The next prime is 195644381951. The reversal of 195644381909 is 909183446591.

195644381909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132771326884 + 62873055025 = 364378^2 + 250745^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-195644381909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (195644381209) 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 as a sum of consecutive naturals, namely, 97822190954 + 97822190955.

It is an arithmetic number, because the mean of its divisors is an integer number (97822190955).

Almost surely, 2^195644381909 is an apocalyptic number.

It is an amenable number.

195644381909 is a deficient number, since it is larger than the sum of its proper divisors (1).

195644381909 is an equidigital number, since it uses as much as digits as its factorization.

195644381909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8398080, while the sum is 59.

The spelling of 195644381909 in words is "one hundred ninety-five billion, six hundred forty-four million, three hundred eighty-one thousand, nine hundred nine".