128945489 has 2 divisors, whose sum is σ = 128945490. Its totient is φ = 128945488.

The previous prime is 128945473. The next prime is 128945497. The reversal of 128945489 is 984549821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124701889 + 4243600 = 11167^2 + 2060^2 .

It is a cyclic number.

It is not a de Polignac number, because 128945489 - 2⁴ = 128945473 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (128945389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64472744 + 64472745.

It is an arithmetic number, because the mean of its divisors is an integer number (64472745).

Almost surely, 2^128945489 is an apocalyptic number.

It is an amenable number.

128945489 is a deficient number, since it is larger than the sum of its proper divisors (1).

128945489 is an equidigital number, since it uses as much as digits as its factorization.

128945489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 829440, while the sum is 50.

The square root of 128945489 is about 11355.4167250700. The cubic root of 128945489 is about 505.2062536905.

The spelling of 128945489 in words is "one hundred twenty-eight million, nine hundred forty-five thousand, four hundred eighty-nine".