129916321 has 2 divisors, whose sum is σ = 129916322. Its totient is φ = 129916320.

The previous prime is 129916313. The next prime is 129916333. The reversal of 129916321 is 123619921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98724096 + 31192225 = 9936^2 + 5585^2 .

It is a cyclic number.

It is not a de Polignac number, because 129916321 - 2³ = 129916313 is a prime.

It is not a weakly prime, because it can be changed into another prime (129914321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64958160 + 64958161.

It is an arithmetic number, because the mean of its divisors is an integer number (64958161).

Almost surely, 2^129916321 is an apocalyptic number.

It is an amenable number.

129916321 is a deficient number, since it is larger than the sum of its proper divisors (1).

129916321 is an equidigital number, since it uses as much as digits as its factorization.

129916321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 34.

The square root of 129916321 is about 11398.0840933904. The cubic root of 129916321 is about 506.4709860603.

The spelling of 129916321 in words is "one hundred twenty-nine million, nine hundred sixteen thousand, three hundred twenty-one".