13221312221 has 8 divisors (see below), whose sum is σ = 14241822840. Its totient is φ = 12201299712.

The previous prime is 13221312217. The next prime is 13221312229. The reversal of 13221312221 is 12221312231.

13221312221 is digitally balanced in base 2, 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 2429011225 + 10792300996 = 49285^2 + 103886^2 .

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 13221312221 - 2² = 13221312217 is a prime.

It is a super-3 number, since 3×13221312221³ (a number of 31 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13221312193 and 13221312202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13221312229) 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 7 ways as a sum of consecutive naturals, for example, 68456 + ... + 176433.

It is an arithmetic number, because the mean of its divisors is an integer number (1780227855).

Almost surely, 2^13221312221 is an apocalyptic number.

It is an amenable number.

13221312221 is a deficient number, since it is larger than the sum of its proper divisors (1020510619).

13221312221 is a wasteful number, since it uses less digits than its factorization.

13221312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249055.

The product of its digits is 288, while the sum is 20.

Adding to 13221312221 its reverse (12221312231), we get a palindrome (25442624452).

The spelling of 13221312221 in words is "thirteen billion, two hundred twenty-one million, three hundred twelve thousand, two hundred twenty-one".