168911909 has 2 divisors, whose sum is σ = 168911910. Its totient is φ = 168911908.

The previous prime is 168911887. The next prime is 168911929. The reversal of 168911909 is 909119861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166281025 + 2630884 = 12895^2 + 1622^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168911909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 168911909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168911929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84455954 + 84455955.

It is an arithmetic number, because the mean of its divisors is an integer number (84455955).

Almost surely, 2^168911909 is an apocalyptic number.

It is an amenable number.

168911909 is a deficient number, since it is larger than the sum of its proper divisors (1).

168911909 is an equidigital number, since it uses as much as digits as its factorization.

168911909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 44.

The square root of 168911909 is about 12996.6114429877. The cubic root of 168911909 is about 552.7814024825.

The spelling of 168911909 in words is "one hundred sixty-eight million, nine hundred eleven thousand, nine hundred nine".