168903809 has 2 divisors, whose sum is σ = 168903810. Its totient is φ = 168903808.

The previous prime is 168903803. The next prime is 168903821. The reversal of 168903809 is 908309861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 167780209 + 1123600 = 12953^2 + 1060^2 .

It is an emirp because it is prime and its reverse (908309861) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168903809 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 168903809.

It is not a weakly prime, because it can be changed into another prime (168903803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84451904 + 84451905.

It is an arithmetic number, because the mean of its divisors is an integer number (84451905).

Almost surely, 2^168903809 is an apocalyptic number.

It is an amenable number.

168903809 is a deficient number, since it is larger than the sum of its proper divisors (1).

168903809 is an equidigital number, since it uses as much as digits as its factorization.

168903809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 168903809 is about 12996.2998195640. The cubic root of 168903809 is about 552.7725663167.

The spelling of 168903809 in words is "one hundred sixty-eight million, nine hundred three thousand, eight hundred nine".