221112122221 has 4 divisors (see below), whose sum is σ = 221118793344. Its totient is φ = 221105451100.

The previous prime is 221112122207. The next prime is 221112122263. The reversal of 221112122221 is 122221211122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221112122221 - 2¹⁹ = 221111597933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221112122321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3285595 + ... + 3352216.

It is an arithmetic number, because the mean of its divisors is an integer number (55279698336).

Almost surely, 2^221112122221 is an apocalyptic number.

It is an amenable number.

221112122221 is a deficient number, since it is larger than the sum of its proper divisors (6671123).

221112122221 is an equidigital number, since it uses as much as digits as its factorization.

221112122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6671122.

The product of its digits is 128, while the sum is 19.

Adding to 221112122221 its reverse (122221211122), we get a palindrome (343333333343).

The spelling of 221112122221 in words is "two hundred twenty-one billion, one hundred twelve million, one hundred twenty-two thousand, two hundred twenty-one".