13128309 has 12 divisors (see below), whose sum is σ = 18999552. Its totient is φ = 8735400.

The previous prime is 13128293. The next prime is 13128319. The reversal of 13128309 is 90382131.

13128309 is nontrivially palindromic in base 11.

It is not a de Polignac number, because 13128309 - 2⁴ = 13128293 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13128319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5164 + ... + 7274.

It is an arithmetic number, because the mean of its divisors is an integer number (1583296).

Almost surely, 2^13128309 is an apocalyptic number.

It is an amenable number.

13128309 is a deficient number, since it is larger than the sum of its proper divisors (5871243).

13128309 is a wasteful number, since it uses less digits than its factorization.

13128309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2808 (or 2805 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 13128309 is about 3623.3008431539. The cubic root of 13128309 is about 235.9045206509.

The spelling of 13128309 in words is "thirteen million, one hundred twenty-eight thousand, three hundred nine".