1221021112111 has 4 divisors (see below), whose sum is σ = 1221381405000. Its totient is φ = 1220660819224.

The previous prime is 1221021112081. The next prime is 1221021112147. The reversal of 1221021112111 is 1112111201221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221021112111 - 2¹¹ = 1221021110063 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 (1221021112411) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 180141361 + ... + 180148138.

It is an arithmetic number, because the mean of its divisors is an integer number (305345351250).

Almost surely, 2^{1221021112111} is an apocalyptic number.

1221021112111 is a deficient number, since it is larger than the sum of its proper divisors (360292889).

1221021112111 is an equidigital number, since it uses as much as digits as its factorization.

1221021112111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360292888.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 1221021112111 its reverse (1112111201221), we get a palindrome (2333132313332).

The spelling of 1221021112111 in words is "one trillion, two hundred twenty-one billion, twenty-one million, one hundred twelve thousand, one hundred eleven".