21012222111 has 4 divisors (see below), whose sum is σ = 28016296152. Its totient is φ = 14008148072.

The previous prime is 21012222109. The next prime is 21012222157. The reversal of 21012222111 is 11122221012.

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 21012222111 - 2¹ = 21012222109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012222311) 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, 3502037016 + ... + 3502037021.

It is an arithmetic number, because the mean of its divisors is an integer number (7004074038).

Almost surely, 2^21012222111 is an apocalyptic number.

21012222111 is a deficient number, since it is larger than the sum of its proper divisors (7004074041).

21012222111 is an equidigital number, since it uses as much as digits as its factorization.

21012222111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7004074040.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21012222111 its reverse (11122221012), we get a palindrome (32134443123).

The spelling of 21012222111 in words is "twenty-one billion, twelve million, two hundred twenty-two thousand, one hundred eleven".