13971366665 has 8 divisors (see below), whose sum is σ = 16771327560. Its totient is φ = 11173301632.

The previous prime is 13971366659. The next prime is 13971366667. The reversal of 13971366665 is 56666317931.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 155950144 + 13815416521 = 12488^2 + 117539^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 13971366665 - 2²² = 13967172361 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13971366667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 457700 + ... + 487269.

It is an arithmetic number, because the mean of its divisors is an integer number (2096415945).

Almost surely, 2^13971366665 is an apocalyptic number.

It is an amenable number.

13971366665 is a deficient number, since it is larger than the sum of its proper divisors (2799960895).

13971366665 is an equidigital number, since it uses as much as digits as its factorization.

13971366665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 947931.

The product of its digits is 3674160, while the sum is 53.

The spelling of 13971366665 in words is "thirteen billion, nine hundred seventy-one million, three hundred sixty-six thousand, six hundred sixty-five".