13431543665 has 4 divisors (see below), whose sum is σ = 16117852404. Its totient is φ = 10745234928.

The previous prime is 13431543661. The next prime is 13431543689. The reversal of 13431543665 is 56634513431.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56634513431 = 39581 ⋅1430851.

It can be written as a sum of positive squares in 2 ways, for example, as 1532879104 + 11898664561 = 39152^2 + 109081^2 .

It is a cyclic number.

It is not a de Polignac number, because 13431543665 - 2² = 13431543661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13431543661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1343154362 + ... + 1343154371.

It is an arithmetic number, because the mean of its divisors is an integer number (4029463101).

Almost surely, 2^13431543665 is an apocalyptic number.

It is an amenable number.

13431543665 is a deficient number, since it is larger than the sum of its proper divisors (2686308739).

13431543665 is an equidigital number, since it uses as much as digits as its factorization.

13431543665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2686308738.

The product of its digits is 388800, while the sum is 41.

The spelling of 13431543665 in words is "thirteen billion, four hundred thirty-one million, five hundred forty-three thousand, six hundred sixty-five".