111221100121221 has 12 divisors (see below), whose sum is σ = 160716884266848. Its totient is φ = 74117776653864.

The previous prime is 111221100121207. The next prime is 111221100121223. The reversal of 111221100121221 is 122121001122111.

It is a happy number.

111221100121221 is a `hidden beast` number, since 1 + 1 + 1 + 221 + 100 + 121 + 221 = 666.

It is not a de Polignac number, because 111221100121221 - 2¹⁰ = 111221100120197 is a prime.

It is a super-2 number, since 2×111221100121221² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 111221100121194 and 111221100121203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111221100121223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2468595135 + ... + 2468640188.

It is an arithmetic number, because the mean of its divisors is an integer number (13393073688904).

Almost surely, 2^{111221100121221} is an apocalyptic number.

It is an amenable number.

111221100121221 is a deficient number, since it is larger than the sum of its proper divisors (49495784145627).

111221100121221 is a wasteful number, since it uses less digits than its factorization.

111221100121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4937237832 (or 4937237829 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 111221100121221 its reverse (122121001122111), we get a palindrome (233342101243332).

The spelling of 111221100121221 in words is "one hundred eleven trillion, two hundred twenty-one billion, one hundred million, one hundred twenty-one thousand, two hundred twenty-one".