13728309 has 32 divisors (see below), whose sum is σ = 22370304. Its totient is φ = 7318080.

The previous prime is 13728301. The next prime is 13728329. The reversal of 13728309 is 90382731.

It is not a de Polignac number, because 13728309 - 2³ = 13728301 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 13728309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13728301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20439 + ... + 21099.

It is an arithmetic number, because the mean of its divisors is an integer number (699072).

Almost surely, 2^13728309 is an apocalyptic number.

It is an amenable number.

13728309 is a deficient number, since it is larger than the sum of its proper divisors (8641995).

13728309 is a wasteful number, since it uses less digits than its factorization.

13728309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 737.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 13728309 is about 3705.1732753004. The cubic root of 13728309 is about 239.4449499595. Note that the first 3 decimals are identical.

The spelling of 13728309 in words is "thirteen million, seven hundred twenty-eight thousand, three hundred nine".