68508809 has 2 divisors, whose sum is σ = 68508810. Its totient is φ = 68508808.

The previous prime is 68508787. The next prime is 68508857. The reversal of 68508809 is 90880586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38093584 + 30415225 = 6172^2 + 5515^2 .

It is a cyclic number.

It is not a de Polignac number, because 68508809 - 2¹⁶ = 68443273 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 68508809.

It is not a weakly prime, because it can be changed into another prime (68508409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34254404 + 34254405.

It is an arithmetic number, because the mean of its divisors is an integer number (34254405).

Almost surely, 2^68508809 is an apocalyptic number.

It is an amenable number.

68508809 is a deficient number, since it is larger than the sum of its proper divisors (1).

68508809 is an equidigital number, since it uses as much as digits as its factorization.

68508809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 44.

The square root of 68508809 is about 8277.0048326674. The cubic root of 68508809 is about 409.1810123701.

The spelling of 68508809 in words is "sixty-eight million, five hundred eight thousand, eight hundred nine".