1221011112111 has 32 divisors (see below), whose sum is σ = 1942073131008. Its totient is φ = 667182273120.

The previous prime is 1221011112109. The next prime is 1221011112163. The reversal of 1221011112111 is 1112111101221.

It is not a de Polignac number, because 1221011112111 - 2¹ = 1221011112109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221051112111) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1215066 + ... + 1979496.

It is an arithmetic number, because the mean of its divisors is an integer number (60689785344).

Almost surely, 2^{1221011112111} is an apocalyptic number.

1221011112111 is a deficient number, since it is larger than the sum of its proper divisors (721062018897).

1221011112111 is a wasteful number, since it uses less digits than its factorization.

1221011112111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767771.

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 1221011112111 its reverse (1112111101221), we get a palindrome (2333122213332).

The spelling of 1221011112111 in words is "one trillion, two hundred twenty-one billion, eleven million, one hundred twelve thousand, one hundred eleven".