221221011111 has 16 divisors (see below), whose sum is σ = 303488465280. Its totient is φ = 143255014560.

The previous prime is 221221011091. The next prime is 221221011131. The reversal of 221221011111 is 111110122122.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (221221011091) and next prime (221221011131).

It is not a de Polignac number, because 221221011111 - 2²¹ = 221218913959 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221011131) 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, 4713921 + ... + 4760618.

It is an arithmetic number, because the mean of its divisors is an integer number (18968029080).

Almost surely, 2^221221011111 is an apocalyptic number.

221221011111 is a deficient number, since it is larger than the sum of its proper divisors (82267454169).

221221011111 is a wasteful number, since it uses less digits than its factorization.

221221011111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9474766.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 221221011111 its reverse (111110122122), we get a palindrome (332331133233).

The spelling of 221221011111 in words is "two hundred twenty-one billion, two hundred twenty-one million, eleven thousand, one hundred eleven".