129618109 has 2 divisors, whose sum is σ = 129618110. Its totient is φ = 129618108.

The previous prime is 129618091. The next prime is 129618121. The reversal of 129618109 is 901816921.

Together with previous prime (129618091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74338884 + 55279225 = 8622^2 + 7435^2 .

It is a cyclic number.

It is not a de Polignac number, because 129618109 - 2⁵ = 129618077 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129618169) 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, 64809054 + 64809055.

It is an arithmetic number, because the mean of its divisors is an integer number (64809055).

Almost surely, 2^129618109 is an apocalyptic number.

It is an amenable number.

129618109 is a deficient number, since it is larger than the sum of its proper divisors (1).

129618109 is an equidigital number, since it uses as much as digits as its factorization.

129618109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 37.

The square root of 129618109 is about 11384.9949055764. The cubic root of 129618109 is about 506.0831686421.

The spelling of 129618109 in words is "one hundred twenty-nine million, six hundred eighteen thousand, one hundred nine".