128810509 has 2 divisors, whose sum is σ = 128810510. Its totient is φ = 128810508.

The previous prime is 128810491. The next prime is 128810531. The reversal of 128810509 is 905018821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 97416900 + 31393609 = 9870^2 + 5603^2 .

It is a cyclic number.

It is not a de Polignac number, because 128810509 - 2¹⁷ = 128679437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128810599) 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, 64405254 + 64405255.

It is an arithmetic number, because the mean of its divisors is an integer number (64405255).

Almost surely, 2^128810509 is an apocalyptic number.

It is an amenable number.

128810509 is a deficient number, since it is larger than the sum of its proper divisors (1).

128810509 is an equidigital number, since it uses as much as digits as its factorization.

128810509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 34.

The square root of 128810509 is about 11349.4717498217. The cubic root of 128810509 is about 505.0299090216.

The spelling of 128810509 in words is "one hundred twenty-eight million, eight hundred ten thousand, five hundred nine".