22121122221 has 16 divisors (see below), whose sum is σ = 35751309120. Its totient is φ = 13406740560.

The previous prime is 22121122187. The next prime is 22121122271. The reversal of 22121122221 is 12222112122.

It is a happy number.

It is not a de Polignac number, because 22121122221 - 2¹⁸ = 22120860077 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22121122194 and 22121122203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22121122271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37240650 + ... + 37241243.

It is an arithmetic number, because the mean of its divisors is an integer number (2234456820).

Almost surely, 2^22121122221 is an apocalyptic number.

It is an amenable number.

22121122221 is a deficient number, since it is larger than the sum of its proper divisors (13630186899).

22121122221 is a wasteful number, since it uses less digits than its factorization.

22121122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74481913 (or 74481907 counting only the distinct ones).

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

Adding to 22121122221 its reverse (12222112122), we get a palindrome (34343234343).

The spelling of 22121122221 in words is "twenty-two billion, one hundred twenty-one million, one hundred twenty-two thousand, two hundred twenty-one".