111111221222221 has 32 divisors (see below), whose sum is σ = 124183372313088. Its totient is φ = 98548368522240.

The previous prime is 111111221222201. The next prime is 111111221222263. The reversal of 111111221222221 is 122222122111111.

It is a cyclic number.

It is not a de Polignac number, because 111111221222221 - 2⁵ = 111111221222189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111111221222192 and 111111221222201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111111221222201) 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, 207287671 + ... + 207823003.

It is an arithmetic number, because the mean of its divisors is an integer number (3880730384784).

Almost surely, 2^{111111221222221} is an apocalyptic number.

111111221222221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111111221222221 is a deficient number, since it is larger than the sum of its proper divisors (13072151090867).

111111221222221 is a wasteful number, since it uses less digits than its factorization.

111111221222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536661.

The product of its digits is 128, while the sum is 22.

Adding to 111111221222221 its reverse (122222122111111), we get a palindrome (233333343333332).

The spelling of 111111221222221 in words is "one hundred eleven trillion, one hundred eleven billion, two hundred twenty-one million, two hundred twenty-two thousand, two hundred twenty-one".