128315309 has 2 divisors, whose sum is σ = 128315310. Its totient is φ = 128315308.

The previous prime is 128315287. The next prime is 128315323. The reversal of 128315309 is 903513821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122722084 + 5593225 = 11078^2 + 2365^2 .

It is a cyclic number.

It is not a de Polignac number, because 128315309 - 2¹⁶ = 128249773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128315009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64157654 + 64157655.

It is an arithmetic number, because the mean of its divisors is an integer number (64157655).

Almost surely, 2^128315309 is an apocalyptic number.

It is an amenable number.

128315309 is a deficient number, since it is larger than the sum of its proper divisors (1).

128315309 is an equidigital number, since it uses as much as digits as its factorization.

128315309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 128315309 is about 11327.6347487020. The cubic root of 128315309 is about 504.3818977614.

The spelling of 128315309 in words is "one hundred twenty-eight million, three hundred fifteen thousand, three hundred nine".