221121111111 has 16 divisors (see below), whose sum is σ = 312464726784. Its totient is φ = 138612104064.

The previous prime is 221121111109. The next prime is 221121111131. The reversal of 221121111111 is 111111121122.

It is not a de Polignac number, because 221121111111 - 2¹ = 221121111109 is a prime.

221121111111 is a modest number, since divided by 1111111 gives 22112 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121111131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1985161 + ... + 2093586.

It is an arithmetic number, because the mean of its divisors is an integer number (19529045424).

Almost surely, 2^221121111111 is an apocalyptic number.

221121111111 is a deficient number, since it is larger than the sum of its proper divisors (91343615673).

221121111111 is a wasteful number, since it uses less digits than its factorization.

221121111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4079830.

The product of its digits is 8, while the sum is 15.

Adding to 221121111111 its reverse (111111121122), we get a palindrome (332232232233).

The spelling of 221121111111 in words is "two hundred twenty-one billion, one hundred twenty-one million, one hundred eleven thousand, one hundred eleven".