12221131221 has 24 divisors (see below), whose sum is σ = 19120568376. Its totient is φ = 7477211520.

The previous prime is 12221131201. The next prime is 12221131249. The reversal of 12221131221 is 12213112221.

12221131221 is a `hidden beast` number, since 122 + 211 + 312 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2765708100 + 9455423121 = 52590^2 + 97239^2 .

It is not a de Polignac number, because 12221131221 - 2⁹ = 12221130709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12221131194 and 12221131203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12221131201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 281650 + ... + 322131.

It is an arithmetic number, because the mean of its divisors is an integer number (796690349).

Almost surely, 2^12221131221 is an apocalyptic number.

It is an amenable number.

12221131221 is a deficient number, since it is larger than the sum of its proper divisors (6899437155).

12221131221 is a wasteful number, since it uses less digits than its factorization.

12221131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 603973 (or 603970 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

Adding to 12221131221 its reverse (12213112221), we get a palindrome (24434243442).

The spelling of 12221131221 in words is "twelve billion, two hundred twenty-one million, one hundred thirty-one thousand, two hundred twenty-one".