221021221111 has 4 divisors (see below), whose sum is σ = 221181266824. Its totient is φ = 220861175400.

The previous prime is 221021221087. The next prime is 221021221181. The reversal of 221021221111 is 111122120122.

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 221021221111 - 2¹⁷ = 221021090039 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 (221021221181) 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, 80020785 + ... + 80023546.

It is an arithmetic number, because the mean of its divisors is an integer number (55295316706).

Almost surely, 2^221021221111 is an apocalyptic number.

221021221111 is a deficient number, since it is larger than the sum of its proper divisors (160045713).

221021221111 is a wasteful number, since it uses less digits than its factorization.

221021221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160045712.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 221021221111 its reverse (111122120122), we get a palindrome (332143341233).

The spelling of 221021221111 in words is "two hundred twenty-one billion, twenty-one million, two hundred twenty-one thousand, one hundred eleven".