13205865 has 16 divisors (see below), whose sum is σ = 21175488. Its totient is φ = 7027776.

The previous prime is 13205849. The next prime is 13205869. The reversal of 13205865 is 56850231.

13205865 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13205865 - 2⁴ = 13205849 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13205869) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10774 + ... + 11936.

It is an arithmetic number, because the mean of its divisors is an integer number (1323468).

Almost surely, 2^13205865 is an apocalyptic number.

13205865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

13205865 is a deficient number, since it is larger than the sum of its proper divisors (7969623).

13205865 is a wasteful number, since it uses less digits than its factorization.

13205865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1928.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 13205865 is about 3633.9874793400. The cubic root of 13205865 is about 236.3681472826.

The spelling of 13205865 in words is "thirteen million, two hundred five thousand, eight hundred sixty-five".