13156631666 has 16 divisors (see below), whose sum is σ = 20625940440. Its totient is φ = 6285995520.

The previous prime is 13156631647. The next prime is 13156631689. The reversal of 13156631666 is 66613665131.

It is a happy number.

13156631666 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8329300225 + 4827331441 = 91265^2 + 69479^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1163645 + ... + 1174896.

Almost surely, 2^13156631666 is an apocalyptic number.

13156631666 is a deficient number, since it is larger than the sum of its proper divisors (7469308774).

13156631666 is a wasteful number, since it uses less digits than its factorization.

13156631666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2338669.

The product of its digits is 349920, while the sum is 44.

The spelling of 13156631666 in words is "thirteen billion, one hundred fifty-six million, six hundred thirty-one thousand, six hundred sixty-six".