129855109 has 2 divisors, whose sum is σ = 129855110. Its totient is φ = 129855108.

The previous prime is 129855083. The next prime is 129855113. The reversal of 129855109 is 901558921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87890625 + 41964484 = 9375^2 + 6478^2 .

It is a cyclic number.

It is not a de Polignac number, because 129855109 - 2⁷ = 129854981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129855169) 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, 64927554 + 64927555.

It is an arithmetic number, because the mean of its divisors is an integer number (64927555).

Almost surely, 2^129855109 is an apocalyptic number.

It is an amenable number.

129855109 is a deficient number, since it is larger than the sum of its proper divisors (1).

129855109 is an equidigital number, since it uses as much as digits as its factorization.

129855109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32400, while the sum is 40.

The square root of 129855109 is about 11395.3985889042. The cubic root of 129855109 is about 506.3914297940.

The spelling of 129855109 in words is "one hundred twenty-nine million, eight hundred fifty-five thousand, one hundred nine".