12031321221 has 6 divisors (see below), whose sum is σ = 17378575110. Its totient is φ = 8020880808.

The previous prime is 12031321201. The next prime is 12031321223. The reversal of 12031321221 is 12212313021.

12031321221 is a `hidden beast` number, since 120 + 3 + 1 + 321 + 221 = 666.

12031321221 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., 11233880100 + 797441121 = 105990^2 + 28239^2 .

It is not a de Polignac number, because 12031321221 - 2¹¹ = 12031319173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12031321194 and 12031321203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12031321223) 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, 668406726 + ... + 668406743.

It is an arithmetic number, because the mean of its divisors is an integer number (2896429185).

Almost surely, 2^12031321221 is an apocalyptic number.

It is an amenable number.

12031321221 is a deficient number, since it is larger than the sum of its proper divisors (5347253889).

12031321221 is a wasteful number, since it uses less digits than its factorization.

12031321221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336813475 (or 1336813472 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 12031321221 its reverse (12212313021), we get a palindrome (24243634242).

The spelling of 12031321221 in words is "twelve billion, thirty-one million, three hundred twenty-one thousand, two hundred twenty-one".