129030921 has 32 divisors (see below), whose sum is σ = 195920000. Its totient is φ = 83903040.

The previous prime is 129030907. The next prime is 129030949.

129030921 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 129030921 - 2⁷ = 129030793 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129030521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 258330 + ... + 258828.

It is an arithmetic number, because the mean of its divisors is an integer number (6122500).

Almost surely, 2^129030921 is an apocalyptic number.

It is an amenable number.

129030921 is a deficient number, since it is larger than the sum of its proper divisors (66889079).

129030921 is a wasteful number, since it uses less digits than its factorization.

129030921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726 (or 720 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 129030921 is about 11359.1778311637. The cubic root of 129030921 is about 505.3178027710.

The spelling of 129030921 in words is "one hundred twenty-nine million, thirty thousand, nine hundred twenty-one".