129209117 has 2 divisors, whose sum is σ = 129209118. Its totient is φ = 129209116.

The previous prime is 129209111. The next prime is 129209159. The reversal of 129209117 is 711902921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72267001 + 56942116 = 8501^2 + 7546^2 .

It is a cyclic number.

It is not a de Polignac number, because 129209117 - 2⁸ = 129208861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129209111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64604558 + 64604559.

It is an arithmetic number, because the mean of its divisors is an integer number (64604559).

Almost surely, 2^129209117 is an apocalyptic number.

It is an amenable number.

129209117 is a deficient number, since it is larger than the sum of its proper divisors (1).

129209117 is an equidigital number, since it uses as much as digits as its factorization.

129209117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2268, while the sum is 32.

The square root of 129209117 is about 11367.0188264118. The cubic root of 129209117 is about 505.5503160070.

The spelling of 129209117 in words is "one hundred twenty-nine million, two hundred nine thousand, one hundred seventeen".