111331121221 has 16 divisors (see below), whose sum is σ = 116775106560. Its totient is φ = 106012258560.

The previous prime is 111331121203. The next prime is 111331121227. The reversal of 111331121221 is 122121133111.

It is a cyclic number.

It is not a de Polignac number, because 111331121221 - 2⁵ = 111331121189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111331121227) 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 15 ways as a sum of consecutive naturals, for example, 639981 + ... + 795133.

It is an arithmetic number, because the mean of its divisors is an integer number (7298444160).

Almost surely, 2^111331121221 is an apocalyptic number.

It is an amenable number.

111331121221 is a deficient number, since it is larger than the sum of its proper divisors (5443985339).

111331121221 is a wasteful number, since it uses less digits than its factorization.

111331121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155556.

The product of its digits is 72, while the sum is 19.

Adding to 111331121221 its reverse (122121133111), we get a palindrome (233452254332).

The spelling of 111331121221 in words is "one hundred eleven billion, three hundred thirty-one million, one hundred twenty-one thousand, two hundred twenty-one".