68309809 has 2 divisors, whose sum is σ = 68309810. Its totient is φ = 68309808.

The previous prime is 68309767. The next prime is 68309821. The reversal of 68309809 is 90890386.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37173409 + 31136400 = 6097^2 + 5580^2 .

It is a cyclic number.

It is not a de Polignac number, because 68309809 - 2¹¹ = 68307761 is a prime.

It is not a weakly prime, because it can be changed into another prime (68309869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34154904 + 34154905.

It is an arithmetic number, because the mean of its divisors is an integer number (34154905).

Almost surely, 2^68309809 is an apocalyptic number.

It is an amenable number.

68309809 is a deficient number, since it is larger than the sum of its proper divisors (1).

68309809 is an equidigital number, since it uses as much as digits as its factorization.

68309809 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 43.

The square root of 68309809 is about 8264.9748335975. The cubic root of 68309809 is about 408.7844405449.

The spelling of 68309809 in words is "sixty-eight million, three hundred nine thousand, eight hundred nine".