221111112121 has 4 divisors (see below), whose sum is σ = 221113088512. Its totient is φ = 221109135732.

The previous prime is 221111112113. The next prime is 221111112127. The reversal of 221111112121 is 121211111122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221111112121 - 2³ = 221111112113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221111112095 and 221111112104.

It is not an unprimeable number, because it can be changed into a prime (221111112127) 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, 809625 + ... + 1047718.

It is an arithmetic number, because the mean of its divisors is an integer number (55278272128).

Almost surely, 2^221111112121 is an apocalyptic number.

It is an amenable number.

221111112121 is a deficient number, since it is larger than the sum of its proper divisors (1976391).

221111112121 is a wasteful number, since it uses less digits than its factorization.

221111112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1976390.

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

Adding to 221111112121 its reverse (121211111122), we get a palindrome (342322223243).

Subtracting from 221111112121 its reverse (121211111122), we obtain a palindrome (99900000999).

The spelling of 221111112121 in words is "two hundred twenty-one billion, one hundred eleven million, one hundred twelve thousand, one hundred twenty-one".