12131122221 has 40 divisors (see below), whose sum is σ = 18350085600. Its totient is φ = 7985973600.

The previous prime is 12131122193. The next prime is 12131122229. The reversal of 12131122221 is 12222113121.

It is not a de Polignac number, because 12131122221 - 2¹¹ = 12131120173 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12131122194 and 12131122203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12131122229) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 3426070 + ... + 3429608.

It is an arithmetic number, because the mean of its divisors is an integer number (458752140).

Almost surely, 2^12131122221 is an apocalyptic number.

It is an amenable number.

12131122221 is a deficient number, since it is larger than the sum of its proper divisors (6218963379).

12131122221 is a wasteful number, since it uses less digits than its factorization.

12131122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4071 (or 4062 counting only the distinct ones).

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

Adding to 12131122221 its reverse (12222113121), we get a palindrome (24353235342).

The spelling of 12131122221 in words is "twelve billion, one hundred thirty-one million, one hundred twenty-two thousand, two hundred twenty-one".