13221811666 has 16 divisors (see below), whose sum is σ = 22754163456. Its totient is φ = 5644440576.

The previous prime is 13221811663. The next prime is 13221811697. The reversal of 13221811666 is 66611812231.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (13221811663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1833786 + ... + 1840981.

It is an arithmetic number, because the mean of its divisors is an integer number (1422135216).

Almost surely, 2^13221811666 is an apocalyptic number.

13221811666 is a deficient number, since it is larger than the sum of its proper divisors (9532351790).

13221811666 is a wasteful number, since it uses less digits than its factorization.

13221811666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3675033.

The product of its digits is 20736, while the sum is 37.

The spelling of 13221811666 in words is "thirteen billion, two hundred twenty-one million, eight hundred eleven thousand, six hundred sixty-six".