129161809 has 8 divisors (see below), whose sum is σ = 151046720. Its totient is φ = 108135216.

The previous prime is 129161803. The next prime is 129161821. The reversal of 129161809 is 908161921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 129161809 - 2²¹ = 127064657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129161803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 214254 + ... + 214855.

It is an arithmetic number, because the mean of its divisors is an integer number (18880840).

Almost surely, 2^129161809 is an apocalyptic number.

It is an amenable number.

129161809 is a deficient number, since it is larger than the sum of its proper divisors (21884911).

129161809 is an equidigital number, since it uses as much as digits as its factorization.

129161809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429159.

The product of its (nonzero) digits is 7776, while the sum is 37.

The square root of 129161809 is about 11364.9377033048. The cubic root of 129161809 is about 505.4886085610.

The spelling of 129161809 in words is "one hundred twenty-nine million, one hundred sixty-one thousand, eight hundred nine".