129831817 has 2 divisors, whose sum is σ = 129831818. Its totient is φ = 129831816.

The previous prime is 129831797. The next prime is 129831833. The reversal of 129831817 is 718138921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 125686521 + 4145296 = 11211^2 + 2036^2 .

It is an emirp because it is prime and its reverse (718138921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 129831817 - 2¹¹ = 129829769 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 129831817.

It is not a weakly prime, because it can be changed into another prime (129831847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64915908 + 64915909.

It is an arithmetic number, because the mean of its divisors is an integer number (64915909).

Almost surely, 2^129831817 is an apocalyptic number.

It is an amenable number.

129831817 is a deficient number, since it is larger than the sum of its proper divisors (1).

129831817 is an equidigital number, since it uses as much as digits as its factorization.

129831817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 40.

The square root of 129831817 is about 11394.3765516153. The cubic root of 129831817 is about 506.3611509841.

The spelling of 129831817 in words is "one hundred twenty-nine million, eight hundred thirty-one thousand, eight hundred seventeen".