129323921 has 2 divisors, whose sum is σ = 129323922. Its totient is φ = 129323920.

The previous prime is 129323911. The next prime is 129323927.

129323921 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128504896 + 819025 = 11336^2 + 905^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 129323921 - 2²² = 125129617 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (129323927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64661960 + 64661961.

It is an arithmetic number, because the mean of its divisors is an integer number (64661961).

Almost surely, 2^129323921 is an apocalyptic number.

It is an amenable number.

129323921 is a deficient number, since it is larger than the sum of its proper divisors (1).

129323921 is an equidigital number, since it uses as much as digits as its factorization.

129323921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 32.

The square root of 129323921 is about 11372.0675780616. The cubic root of 129323921 is about 505.7000010519.

The spelling of 129323921 in words is "one hundred twenty-nine million, three hundred twenty-three thousand, nine hundred twenty-one".