111221222121 has 16 divisors (see below), whose sum is σ = 164777553600. Its totient is φ = 74145063744.

The previous prime is 111221222087. The next prime is 111221222143. The reversal of 111221222121 is 121222122111.

It is not a de Polignac number, because 111221222121 - 2¹⁴ = 111221205737 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111221222094 and 111221222103.

It is not an unprimeable number, because it can be changed into a prime (111221222221) 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, 1235985 + ... + 1322913.

It is an arithmetic number, because the mean of its divisors is an integer number (10298597100).

Almost surely, 2^111221222121 is an apocalyptic number.

It is an amenable number.

111221222121 is a deficient number, since it is larger than the sum of its proper divisors (53556331479).

111221222121 is an equidigital number, since it uses as much as digits as its factorization.

111221222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134325 (or 134319 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

Adding to 111221222121 its reverse (121222122111), we get a palindrome (232443344232).

The spelling of 111221222121 in words is "one hundred eleven billion, two hundred twenty-one million, two hundred twenty-two thousand, one hundred twenty-one".