129839321 has 2 divisors, whose sum is σ = 129839322. Its totient is φ = 129839320.

The previous prime is 129839291. The next prime is 129839323. The reversal of 129839321 is 123938921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 102799321 + 27040000 = 10139^2 + 5200^2 .

It is a cyclic number.

It is not a de Polignac number, because 129839321 - 2¹⁰ = 129838297 is a prime.

Together with 129839323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (129839323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64919660 + 64919661.

It is an arithmetic number, because the mean of its divisors is an integer number (64919661).

Almost surely, 2^129839321 is an apocalyptic number.

It is an amenable number.

129839321 is a deficient number, since it is larger than the sum of its proper divisors (1).

129839321 is an equidigital number, since it uses as much as digits as its factorization.

129839321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 38.

The square root of 129839321 is about 11394.7058320959. The cubic root of 129839321 is about 506.3709063249.

The spelling of 129839321 in words is "one hundred twenty-nine million, eight hundred thirty-nine thousand, three hundred twenty-one".