21220111010111 has 16 divisors (see below), whose sum is σ = 23105432528640. Its totient is φ = 19371382579200.

The previous prime is 21220111010101. The next prime is 21220111010123. The reversal of 21220111010111 is 11101011102212.

It is a cyclic number.

It is not a de Polignac number, because 21220111010111 - 2¹⁰ = 21220111009087 is a prime.

It is a super-2 number, since 2×21220111010111² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220111010101) 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, 8230466 + ... + 10496703.

It is an arithmetic number, because the mean of its divisors is an integer number (1444089533040).

Almost surely, 2^{21220111010111} is an apocalyptic number.

21220111010111 is a deficient number, since it is larger than the sum of its proper divisors (1885321518529).

21220111010111 is a wasteful number, since it uses less digits than its factorization.

21220111010111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18728146.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21220111010111 its reverse (11101011102212), we get a palindrome (32321122112323).

The spelling of 21220111010111 in words is "twenty-one trillion, two hundred twenty billion, one hundred eleven million, ten thousand, one hundred eleven".