128384989 has 2 divisors, whose sum is σ = 128384990. Its totient is φ = 128384988.

The previous prime is 128384959. The next prime is 128385007. The reversal of 128384989 is 989483821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83722500 + 44662489 = 9150^2 + 6683^2 .

It is a cyclic number.

It is not a de Polignac number, because 128384989 - 2²⁵ = 94830557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128384909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64192494 + 64192495.

It is an arithmetic number, because the mean of its divisors is an integer number (64192495).

Almost surely, 2^128384989 is an apocalyptic number.

It is an amenable number.

128384989 is a deficient number, since it is larger than the sum of its proper divisors (1).

128384989 is an equidigital number, since it uses as much as digits as its factorization.

128384989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 995328, while the sum is 52.

The square root of 128384989 is about 11330.7099954063. The cubic root of 128384989 is about 504.4731806361.

The spelling of 128384989 in words is "one hundred twenty-eight million, three hundred eighty-four thousand, nine hundred eighty-nine".