128663309 has 2 divisors, whose sum is σ = 128663310. Its totient is φ = 128663308.

The previous prime is 128663291. The next prime is 128663347. The reversal of 128663309 is 903366821.

It is an a-pointer prime, because the next prime (128663347) can be obtained adding 128663309 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126112900 + 2550409 = 11230^2 + 1597^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128663309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128663389) 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, 64331654 + 64331655.

It is an arithmetic number, because the mean of its divisors is an integer number (64331655).

Almost surely, 2^128663309 is an apocalyptic number.

It is an amenable number.

128663309 is a deficient number, since it is larger than the sum of its proper divisors (1).

128663309 is an equidigital number, since it uses as much as digits as its factorization.

128663309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 128663309 is about 11342.9850127733. The cubic root of 128663309 is about 504.8374590447.

The spelling of 128663309 in words is "one hundred twenty-eight million, six hundred sixty-three thousand, three hundred nine".