13228231221 has 6 divisors (see below), whose sum is σ = 19107445110. Its totient is φ = 8818820808.

The previous prime is 13228231217. The next prime is 13228231241. The reversal of 13228231221 is 12213282231.

13228231221 is a `hidden beast` number, since 1 + 322 + 8 + 2 + 312 + 21 = 666.

13228231221 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 only one way, i.e., 13228220196 + 11025 = 115014^2 + 105^2 .

It is not a de Polignac number, because 13228231221 - 2² = 13228231217 is a prime.

It is a super-3 number, since 3×13228231221³ (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13228231241) 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 5 ways as a sum of consecutive naturals, for example, 734901726 + ... + 734901743.

It is an arithmetic number, because the mean of its divisors is an integer number (3184574185).

Almost surely, 2^13228231221 is an apocalyptic number.

It is an amenable number.

13228231221 is a deficient number, since it is larger than the sum of its proper divisors (5879213889).

13228231221 is a wasteful number, since it uses less digits than its factorization.

13228231221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1469803475 (or 1469803472 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The spelling of 13228231221 in words is "thirteen billion, two hundred twenty-eight million, two hundred thirty-one thousand, two hundred twenty-one".