129000921 has 16 divisors (see below), whose sum is σ = 196988928. Its totient is φ = 73558800.

The previous prime is 129000901. The next prime is 129000923.

129000921 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 129000921 - 2¹⁸ = 128738777 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 129000891 and 129000900.

It is not an unprimeable number, because it can be changed into a prime (129000923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4056 + ... + 16566.

It is an arithmetic number, because the mean of its divisors is an integer number (12311808).

Almost surely, 2^129000921 is an apocalyptic number.

It is an amenable number.

129000921 is a deficient number, since it is larger than the sum of its proper divisors (67988007).

129000921 is a wasteful number, since it uses less digits than its factorization.

129000921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13012.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 129000921 is about 11357.8572362924. The cubic root of 129000921 is about 505.2786372000.

It can be divided in two parts, 129000 and 921, that added together give a palindrome (129921).

The spelling of 129000921 in words is "one hundred twenty-nine million, nine hundred twenty-one", and thus it is an aban number.