168998909 has 2 divisors, whose sum is σ = 168998910. Its totient is φ = 168998908.

The previous prime is 168998867. The next prime is 168998923. The reversal of 168998909 is 909899861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 101808100 + 67190809 = 10090^2 + 8197^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168998909 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168998509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84499454 + 84499455.

It is an arithmetic number, because the mean of its divisors is an integer number (84499455).

Almost surely, 2^168998909 is an apocalyptic number.

It is an amenable number.

168998909 is a deficient number, since it is larger than the sum of its proper divisors (1).

168998909 is an equidigital number, since it uses as much as digits as its factorization.

168998909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2519424, while the sum is 59.

The square root of 168998909 is about 12999.9580383938. The cubic root of 168998909 is about 552.8762916428.

The spelling of 168998909 in words is "one hundred sixty-eight million, nine hundred ninety-eight thousand, nine hundred nine".