129368809 has 2 divisors, whose sum is σ = 129368810. Its totient is φ = 129368808.

The previous prime is 129368801. The next prime is 129368819. The reversal of 129368809 is 908863921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115885225 + 13483584 = 10765^2 + 3672^2 .

It is a cyclic number.

It is not a de Polignac number, because 129368809 - 2³ = 129368801 is a prime.

It is not a weakly prime, because it can be changed into another prime (129368801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64684404 + 64684405.

It is an arithmetic number, because the mean of its divisors is an integer number (64684405).

Almost surely, 2^129368809 is an apocalyptic number.

It is an amenable number.

129368809 is a deficient number, since it is larger than the sum of its proper divisors (1).

129368809 is an equidigital number, since it uses as much as digits as its factorization.

129368809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 186624, while the sum is 46.

The square root of 129368809 is about 11374.0410145207. The cubic root of 129368809 is about 505.7585033398.

The spelling of 129368809 in words is "one hundred twenty-nine million, three hundred sixty-eight thousand, eight hundred nine".