129688009 has 8 divisors (see below), whose sum is σ = 141574752. Its totient is φ = 117817440.

The previous prime is 129688003. The next prime is 129688049. The reversal of 129688009 is 900886921.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 129688009 - 2³ = 129688001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129688001) 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, 17962 + ... + 24124.

It is an arithmetic number, because the mean of its divisors is an integer number (17696844).

Almost surely, 2^129688009 is an apocalyptic number.

It is an amenable number.

129688009 is a deficient number, since it is larger than the sum of its proper divisors (11886743).

129688009 is a wasteful number, since it uses less digits than its factorization.

129688009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8087.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 129688009 is about 11388.0643219118. The cubic root of 129688009 is about 506.1741252136.

The spelling of 129688009 in words is "one hundred twenty-nine million, six hundred eighty-eight thousand, nine".