129328009 has 4 divisors (see below), whose sum is σ = 129401620. Its totient is φ = 129254400.

The previous prime is 129327971. The next prime is 129328013. The reversal of 129328009 is 900823921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16224784 + 113103225 = 4028^2 + 10635^2 .

It is a cyclic number.

It is not a de Polignac number, because 129328009 - 2¹¹ = 129325961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129326009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34104 + ... + 37705.

It is an arithmetic number, because the mean of its divisors is an integer number (32350405).

Almost surely, 2^129328009 is an apocalyptic number.

It is an amenable number.

129328009 is a deficient number, since it is larger than the sum of its proper divisors (73611).

129328009 is an equidigital number, since it uses as much as digits as its factorization.

129328009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73610.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 129328009 is about 11372.2473152847. The cubic root of 129328009 is about 505.7053294804.

The spelling of 129328009 in words is "one hundred twenty-nine million, three hundred twenty-eight thousand, nine".