129312961 has 2 divisors, whose sum is σ = 129312962. Its totient is φ = 129312960.

The previous prime is 129312959. The next prime is 129312971. The reversal of 129312961 is 169213921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76895361 + 52417600 = 8769^2 + 7240^2 .

It is a cyclic number.

It is not a de Polignac number, because 129312961 - 2¹ = 129312959 is a prime.

Together with 129312959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (129312971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64656480 + 64656481.

It is an arithmetic number, because the mean of its divisors is an integer number (64656481).

Almost surely, 2^129312961 is an apocalyptic number.

It is an amenable number.

129312961 is a deficient number, since it is larger than the sum of its proper divisors (1).

129312961 is an equidigital number, since it uses as much as digits as its factorization.

129312961 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 129312961 is about 11371.5856853827. The cubic root of 129312961 is about 505.6857148870.

The spelling of 129312961 in words is "one hundred twenty-nine million, three hundred twelve thousand, nine hundred sixty-one".