111212221222221 has 32 divisors (see below), whose sum is σ = 180472040057088. Its totient is φ = 59465882864640.

The previous prime is 111212221222217. The next prime is 111212221222229. The reversal of 111212221222221 is 122222122212111.

It is not a de Polignac number, because 111212221222221 - 2² = 111212221222217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111212221222191 and 111212221222200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111212221222229) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 900281670 + ... + 900405191.

It is an arithmetic number, because the mean of its divisors is an integer number (5639751251784).

Almost surely, 2^{111212221222221} is an apocalyptic number.

It is an amenable number.

111212221222221 is a deficient number, since it is larger than the sum of its proper divisors (69259818834867).

111212221222221 is a wasteful number, since it uses less digits than its factorization.

111212221222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1800687061.

The product of its digits is 512, while the sum is 24.

Adding to 111212221222221 its reverse (122222122212111), we get a palindrome (233434343434332).

The spelling of 111212221222221 in words is "one hundred eleven trillion, two hundred twelve billion, two hundred twenty-one million, two hundred twenty-two thousand, two hundred twenty-one".