129189889 has 2 divisors, whose sum is σ = 129189890. Its totient is φ = 129189888.

The previous prime is 129189871. The next prime is 129189923. The reversal of 129189889 is 988981921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125888400 + 3301489 = 11220^2 + 1817^2 .

It is an emirp because it is prime and its reverse (988981921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 129189889 - 2⁵ = 129189857 is a prime.

It is not a weakly prime, because it can be changed into another prime (129189859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64594944 + 64594945.

It is an arithmetic number, because the mean of its divisors is an integer number (64594945).

Almost surely, 2^129189889 is an apocalyptic number.

It is an amenable number.

129189889 is a deficient number, since it is larger than the sum of its proper divisors (1).

129189889 is an equidigital number, since it uses as much as digits as its factorization.

129189889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 746496, while the sum is 55.

The square root of 129189889 is about 11366.1730146958. The cubic root of 129189889 is about 505.5252372718.

The spelling of 129189889 in words is "one hundred twenty-nine million, one hundred eighty-nine thousand, eight hundred eighty-nine".