13666805 has 4 divisors (see below), whose sum is σ = 16400172. Its totient is φ = 10933440.

The previous prime is 13666787. The next prime is 13666813. The reversal of 13666805 is 50866631.

13666805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9690769 + 3976036 = 3113^2 + 1994^2 .

It is not a de Polignac number, because 13666805 - 2¹² = 13662709 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1366676 + ... + 1366685.

It is an arithmetic number, because the mean of its divisors is an integer number (4100043).

Almost surely, 2^13666805 is an apocalyptic number.

It is an amenable number.

13666805 is a deficient number, since it is larger than the sum of its proper divisors (2733367).

13666805 is an equidigital number, since it uses as much as digits as its factorization.

13666805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2733366.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 13666805 is about 3696.8642117340. The cubic root of 13666805 is about 239.0868366726.

The spelling of 13666805 in words is "thirteen million, six hundred sixty-six thousand, eight hundred five".