13021666221 has 16 divisors (see below), whose sum is σ = 17770565120. Its totient is φ = 8477043120.

The previous prime is 13021666211. The next prime is 13021666237. The reversal of 13021666221 is 12266612031.

13021666221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13021666221 - 2¹⁰ = 13021665197 is a prime.

It is a super-2 number, since 2×13021666221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13021666211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 603306 + ... + 624516.

It is an arithmetic number, because the mean of its divisors is an integer number (1110660320).

Almost surely, 2^13021666221 is an apocalyptic number.

It is an amenable number.

13021666221 is a deficient number, since it is larger than the sum of its proper divisors (4748898899).

13021666221 is a wasteful number, since it uses less digits than its factorization.

13021666221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26016.

The product of its (nonzero) digits is 5184, while the sum is 30.

The spelling of 13021666221 in words is "thirteen billion, twenty-one million, six hundred sixty-six thousand, two hundred twenty-one".