12221122221 has 48 divisors (see below), whose sum is σ = 23166973440. Its totient is φ = 6014489760.

The previous prime is 12221122217. The next prime is 12221122229. The reversal of 12221122221 is 12222112221.

It is a happy number.

It is not a de Polignac number, because 12221122221 - 2² = 12221122217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12221122194 and 12221122203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12221122229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 450915 + ... + 477248.

It is an arithmetic number, because the mean of its divisors is an integer number (482645280).

Almost surely, 2^12221122221 is an apocalyptic number.

12221122221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12221122221 is a deficient number, since it is larger than the sum of its proper divisors (10945851219).

12221122221 is a wasteful number, since it uses less digits than its factorization.

12221122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 928206 (or 928203 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

Adding to 12221122221 its reverse (12222112221), we get a palindrome (24443234442).

The spelling of 12221122221 in words is "twelve billion, two hundred twenty-one million, one hundred twenty-two thousand, two hundred twenty-one".