129312991 has 2 divisors, whose sum is σ = 129312992. Its totient is φ = 129312990.

The previous prime is 129312983. The next prime is 129313007. The reversal of 129312991 is 199213921.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 129312991 - 2³ = 129312983 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 129312991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129312961) 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, 64656495 + 64656496.

It is an arithmetic number, because the mean of its divisors is an integer number (64656496).

Almost surely, 2^129312991 is an apocalyptic number.

129312991 is a deficient number, since it is larger than the sum of its proper divisors (1).

129312991 is an equidigital number, since it uses as much as digits as its factorization.

129312991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 37.

The square root of 129312991 is about 11371.5870044598. The cubic root of 129312991 is about 505.6857539925.

The spelling of 129312991 in words is "one hundred twenty-nine million, three hundred twelve thousand, nine hundred ninety-one".