221220212111 has 4 divisors (see below), whose sum is σ = 221609000400. Its totient is φ = 220831423824.

The previous prime is 221220212077. The next prime is 221220212113. The reversal of 221220212111 is 111212022122.

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 221220212111 - 2¹⁴ = 221220195727 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 221220212111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220212113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194393291 + ... + 194394428.

It is an arithmetic number, because the mean of its divisors is an integer number (55402250100).

Almost surely, 2^221220212111 is an apocalyptic number.

221220212111 is a deficient number, since it is larger than the sum of its proper divisors (388788289).

221220212111 is an equidigital number, since it uses as much as digits as its factorization.

221220212111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388788288.

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

Adding to 221220212111 its reverse (111212022122), we get a palindrome (332432234233).

The spelling of 221220212111 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred twelve thousand, one hundred eleven".