1111112112221 has 12 divisors (see below), whose sum is σ = 1180481821620. Its totient is φ = 1045605949440.

The previous prime is 1111112112211. The next prime is 1111112112241. The reversal of 1111112112221 is 1222112111111.

It can be written as a sum of positive squares in 6 ways, for example, as 816512839321 + 294599272900 = 903611^2 + 542770^2 .

It is not a de Polignac number, because 1111112112221 - 2⁶ = 1111112112157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1111112112221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111112112211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1823261 + ... + 2355101.

It is an arithmetic number, because the mean of its divisors is an integer number (98373485135).

Almost surely, 2^{1111112112221} is an apocalyptic number.

It is an amenable number.

1111112112221 is a deficient number, since it is larger than the sum of its proper divisors (69369709399).

1111112112221 is an equidigital number, since it uses as much as digits as its factorization.

1111112112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539104 (or 539087 counting only the distinct ones).

The product of its digits is 16, while the sum is 17.

Adding to 1111112112221 its reverse (1222112111111), we get a palindrome (2333224223332).

The spelling of 1111112112221 in words is "one trillion, one hundred eleven billion, one hundred twelve million, one hundred twelve thousand, two hundred twenty-one".