129411921 has 8 divisors (see below), whose sum is σ = 172962720. Its totient is φ = 86067872.

The previous prime is 129411917. The next prime is 129411929. The reversal of 129411921 is 129114921.

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 129411921 - 2² = 129411917 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129411929) 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, 50220 + ... + 52733.

It is an arithmetic number, because the mean of its divisors is an integer number (21620340).

Almost surely, 2^129411921 is an apocalyptic number.

It is an amenable number.

129411921 is a deficient number, since it is larger than the sum of its proper divisors (43550799).

129411921 is a wasteful number, since it uses less digits than its factorization.

129411921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103375.

The product of its digits is 1296, while the sum is 30.

The square root of 129411921 is about 11375.9360493983. The cubic root of 129411921 is about 505.8146782379.

The spelling of 129411921 in words is "one hundred twenty-nine million, four hundred eleven thousand, nine hundred twenty-one".