13221668 has 6 divisors (see below), whose sum is σ = 23137926. Its totient is φ = 6610832.

The previous prime is 13221667. The next prime is 13221671. The reversal of 13221668 is 86612231.

It can be written as a sum of positive squares in only one way, i.e., 8168164 + 5053504 = 2858^2 + 2248^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 13221668.

It is not an unprimeable number, because it can be changed into a prime (13221667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1652705 + ... + 1652712.

It is an arithmetic number, because the mean of its divisors is an integer number (3856321).

Almost surely, 2^13221668 is an apocalyptic number.

It is an amenable number.

13221668 is a deficient number, since it is larger than the sum of its proper divisors (9916258).

13221668 is a wasteful number, since it uses less digits than its factorization.

13221668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3305421 (or 3305419 counting only the distinct ones).

The product of its digits is 3456, while the sum is 29.

The square root of 13221668 is about 3636.1611625449. The cubic root of 13221668 is about 236.4623942161.

Adding to 13221668 its reverse (86612231), we get a palindrome (99833899).

The spelling of 13221668 in words is "thirteen million, two hundred twenty-one thousand, six hundred sixty-eight".