221220121222111 has 16 divisors (see below), whose sum is σ = 259125956575488. Its totient is φ = 186613343190400.

The previous prime is 221220121222039. The next prime is 221220121222129. The reversal of 221220121222111 is 111222121022122.

It is a cyclic number.

It is not a de Polignac number, because 221220121222111 - 2²⁵ = 221220087667679 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 (221220121232111) 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, 8330939545 + ... + 8330966098.

It is an arithmetic number, because the mean of its divisors is an integer number (16195372285968).

Almost surely, 2^{221220121222111} is an apocalyptic number.

221220121222111 is a deficient number, since it is larger than the sum of its proper divisors (37905835353377).

221220121222111 is a wasteful number, since it uses less digits than its factorization.

221220121222111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16661905742.

The product of its (nonzero) digits is 256, while the sum is 22.

Adding to 221220121222111 its reverse (111222121022122), we get a palindrome (332442242244233).

The spelling of 221220121222111 in words is "two hundred twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, two hundred twenty-two thousand, one hundred eleven".