129992171 has 2 divisors, whose sum is σ = 129992172. Its totient is φ = 129992170.

The previous prime is 129992153. The next prime is 129992179. The reversal of 129992171 is 171299921.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129992171 is a prime.

It is a Sophie Germain prime.

It is equal to p_7377782 and since 129992171 and 7377782 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (129992179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64996085 + 64996086.

It is an arithmetic number, because the mean of its divisors is an integer number (64996086).

Almost surely, 2^129992171 is an apocalyptic number.

129992171 is a deficient number, since it is larger than the sum of its proper divisors (1).

129992171 is an equidigital number, since it uses as much as digits as its factorization.

129992171 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20412, while the sum is 41.

The square root of 129992171 is about 11401.4109214606. The cubic root of 129992171 is about 506.5695324432.

The spelling of 129992171 in words is "one hundred twenty-nine million, nine hundred ninety-two thousand, one hundred seventy-one".