128699609 has 2 divisors, whose sum is σ = 128699610. Its totient is φ = 128699608.

The previous prime is 128699567. The next prime is 128699671. The reversal of 128699609 is 906996821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 95981209 + 32718400 = 9797^2 + 5720^2 .

It is a cyclic number.

It is not a de Polignac number, because 128699609 - 2⁸ = 128699353 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (128699699) 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, 64349804 + 64349805.

It is an arithmetic number, because the mean of its divisors is an integer number (64349805).

Almost surely, 2^128699609 is an apocalyptic number.

It is an amenable number.

128699609 is a deficient number, since it is larger than the sum of its proper divisors (1).

128699609 is an equidigital number, since it uses as much as digits as its factorization.

128699609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 50.

The square root of 128699609 is about 11344.5850078352. The cubic root of 128699609 is about 504.8849314665.

The spelling of 128699609 in words is "one hundred twenty-eight million, six hundred ninety-nine thousand, six hundred nine".