129991689 has 16 divisors (see below), whose sum is σ = 197279040. Its totient is φ = 84546720.

The previous prime is 129991663. The next prime is 129991703. The reversal of 129991689 is 986199921.

It is not a de Polignac number, because 129991689 - 2⁵ = 129991657 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (129991289) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57607 + ... + 59820.

It is an arithmetic number, because the mean of its divisors is an integer number (12329940).

Almost surely, 2^129991689 is an apocalyptic number.

It is an amenable number.

129991689 is a deficient number, since it is larger than the sum of its proper divisors (67287351).

129991689 is a wasteful number, since it uses less digits than its factorization.

129991689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117477 (or 117471 counting only the distinct ones).

The product of its digits is 629856, while the sum is 54.

The square root of 129991689 is about 11401.3897837062. The cubic root of 129991689 is about 506.5689063367.

The spelling of 129991689 in words is "one hundred twenty-nine million, nine hundred ninety-one thousand, six hundred eighty-nine".