168321137909 has 2 divisors, whose sum is σ = 168321137910. Its totient is φ = 168321137908.

The previous prime is 168321137903. The next prime is 168321137923. The reversal of 168321137909 is 909731123861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 124130791684 + 44190346225 = 352322^2 + 210215^2 .

It is a cyclic number.

It is not a de Polignac number, because 168321137909 - 2¹⁶ = 168321072373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168321137903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84160568954 + 84160568955.

It is an arithmetic number, because the mean of its divisors is an integer number (84160568955).

Almost surely, 2^168321137909 is an apocalyptic number.

It is an amenable number.

168321137909 is a deficient number, since it is larger than the sum of its proper divisors (1).

168321137909 is an equidigital number, since it uses as much as digits as its factorization.

168321137909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 489888, while the sum is 50.

The spelling of 168321137909 in words is "one hundred sixty-eight billion, three hundred twenty-one million, one hundred thirty-seven thousand, nine hundred nine".