13666311409 has 3 divisors (see below), whose sum is σ = 13666428313. Its totient is φ = 13666194506.

The previous prime is 13666311403. The next prime is 13666311433. The reversal of 13666311409 is 90411366631.

It is a happy number.

The square root of 13666311409 is 116903.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 13666311409 - 2¹¹ = 13666309361 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13666311403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 58452 + ... + 175354.

Almost surely, 2^13666311409 is an apocalyptic number.

13666311409 is the 116903-rd square number.

13666311409 is the 58452-nd centered octagonal number.

It is an amenable number.

13666311409 is a deficient number, since it is larger than the sum of its proper divisors (116904).

13666311409 is an frugal number, since it uses more digits than its factorization.

13666311409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233806 (or 116903 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 40.

The spelling of 13666311409 in words is "thirteen billion, six hundred sixty-six million, three hundred eleven thousand, four hundred nine".