129929921 has 12 divisors (see below), whose sum is σ = 149028096. Its totient is φ = 112980120.

The previous prime is 129929909. The next prime is 129929927.

It is a happy number.

129929921 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 129929921 - 2⁶ = 129929857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129929927) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20561 + ... + 26126.

It is an arithmetic number, because the mean of its divisors is an integer number (12419008).

Almost surely, 2^129929921 is an apocalyptic number.

129929921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

129929921 is a deficient number, since it is larger than the sum of its proper divisors (19098175).

129929921 is a wasteful number, since it uses less digits than its factorization.

129929921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46732 (or 46721 counting only the distinct ones).

The product of its digits is 52488, while the sum is 44.

The square root of 129929921 is about 11398.6806692705. The cubic root of 129929921 is about 506.4886583718.

The spelling of 129929921 in words is "one hundred twenty-nine million, nine hundred twenty-nine thousand, nine hundred twenty-one".