129273921 has 32 divisors (see below), whose sum is σ = 220849920. Its totient is φ = 73204992.

The previous prime is 129273913. The next prime is 129273931. The reversal of 129273921 is 129372921.

It is not a de Polignac number, because 129273921 - 2³ = 129273913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129273901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18331 + ... + 24383.

It is an arithmetic number, because the mean of its divisors is an integer number (6901560).

Almost surely, 2^129273921 is an apocalyptic number.

It is an amenable number.

129273921 is a deficient number, since it is larger than the sum of its proper divisors (91575999).

129273921 is a wasteful number, since it uses less digits than its factorization.

129273921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6182 (or 6176 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 129273921 is about 11369.8689966068. The cubic root of 129273921 is about 505.6348203821.

The spelling of 129273921 in words is "one hundred twenty-nine million, two hundred seventy-three thousand, nine hundred twenty-one".