1999608095809 has 2 divisors, whose sum is σ = 1999608095810. Its totient is φ = 1999608095808.

The previous prime is 1999608095789. The next prime is 1999608095857. The reversal of 1999608095809 is 9085908069991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1622400850225 + 377207245584 = 1273735^2 + 614172^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999608095809 - 2⁹ = 1999608095297 is a prime.

It is not a weakly prime, because it can be changed into another prime (1999608095509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999804047904 + 999804047905.

It is an arithmetic number, because the mean of its divisors is an integer number (999804047905).

Almost surely, 2^{1999608095809} is an apocalyptic number.

It is an amenable number.

1999608095809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999608095809 is an equidigital number, since it uses as much as digits as its factorization.

1999608095809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 113374080, while the sum is 73.

The spelling of 1999608095809 in words is "one trillion, nine hundred ninety-nine billion, six hundred eight million, ninety-five thousand, eight hundred nine".