111111112222221 has 64 divisors (see below), whose sum is σ = 153787014144000. Its totient is φ = 71301959963136.

The previous prime is 111111112222217. The next prime is 111111112222237. The reversal of 111111112222221 is 122222211111111.

It is not a de Polignac number, because 111111112222221 - 2² = 111111112222217 is a prime.

111111112222221 is a modest number, since divided by 12222221 gives 1111111 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111111112622221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 20103328560 + ... + 20103334086.

It is an arithmetic number, because the mean of its divisors is an integer number (2402922096000).

Almost surely, 2^{111111112222221} is an apocalyptic number.

It is an amenable number.

111111112222221 is a deficient number, since it is larger than the sum of its proper divisors (42675901921779).

111111112222221 is a wasteful number, since it uses less digits than its factorization.

111111112222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10618.

The product of its digits is 64, while the sum is 21.

Adding to 111111112222221 its reverse (122222211111111), we get a palindrome (233333323333332).

The spelling of 111111112222221 in words is "one hundred eleven trillion, one hundred eleven billion, one hundred twelve million, two hundred twenty-two thousand, two hundred twenty-one".