1111121212221 has 96 divisors (see below), whose sum is σ = 1706581094400. Its totient is φ = 695815142400.

The previous prime is 1111121212189. The next prime is 1111121212237. The reversal of 1111121212221 is 1222121211111.

It is a happy number.

1111121212221 is a `hidden beast` number, since 1 + 111 + 121 + 212 + 221 = 666.

It is not a de Polignac number, because 1111121212221 - 2⁵ = 1111121212189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1111121212194 and 1111121212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111121212261) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 252009865 + ... + 252014273.

It is an arithmetic number, because the mean of its divisors is an integer number (17776886400).

Almost surely, 2^{1111121212221} is an apocalyptic number.

It is an amenable number.

1111121212221 is a deficient number, since it is larger than the sum of its proper divisors (595459882179).

1111121212221 is a wasteful number, since it uses less digits than its factorization.

1111121212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4739 (or 4736 counting only the distinct ones).

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

Adding to 1111121212221 its reverse (1222121211111), we get a palindrome (2333242423332).

The spelling of 1111121212221 in words is "one trillion, one hundred eleven billion, one hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".