1221020222111 has 4 divisors (see below), whose sum is σ = 1221022992000. Its totient is φ = 1221017452224.

The previous prime is 1221020222053. The next prime is 1221020222113. The reversal of 1221020222111 is 1112220201221.

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 1221020222111 - 2¹⁸ = 1221019959967 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221020222111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221020222113) 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 3 ways as a sum of consecutive naturals, for example, 559871 + ... + 1659968.

It is an arithmetic number, because the mean of its divisors is an integer number (305255748000).

Almost surely, 2^{1221020222111} is an apocalyptic number.

1221020222111 is a deficient number, since it is larger than the sum of its proper divisors (2769889).

1221020222111 is an equidigital number, since it uses as much as digits as its factorization.

1221020222111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2769888.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1221020222111 its reverse (1112220201221), we get a palindrome (2333240423332).

The spelling of 1221020222111 in words is "one trillion, two hundred twenty-one billion, twenty million, two hundred twenty-two thousand, one hundred eleven".