129991599 has 12 divisors (see below), whose sum is σ = 188058312. Its totient is φ = 86526000.

The previous prime is 129991579. The next prime is 129991627. The reversal of 129991599 is 995199921.

It is not a de Polignac number, because 129991599 - 2⁵ = 129991567 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129991579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4977 + ... + 16874.

It is an arithmetic number, because the mean of its divisors is an integer number (15671526).

Almost surely, 2^129991599 is an apocalyptic number.

129991599 is a deficient number, since it is larger than the sum of its proper divisors (58066713).

129991599 is a wasteful number, since it uses less digits than its factorization.

129991599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22518 (or 22515 counting only the distinct ones).

The product of its digits is 590490, while the sum is 54.

The square root of 129991599 is about 11401.3858368183. The cubic root of 129991599 is about 506.5687894287.

The spelling of 129991599 in words is "one hundred twenty-nine million, nine hundred ninety-one thousand, five hundred ninety-nine".