21212222101111 has 4 divisors (see below), whose sum is σ = 21257644418712. Its totient is φ = 21166799783512.

The previous prime is 21212222101061. The next prime is 21212222101127. The reversal of 21212222101111 is 11110122221212.

It is a happy number.

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 21212222101111 - 2²¹ = 21212220003959 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 (21212222101711) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22711158100 + ... + 22711159033.

It is an arithmetic number, because the mean of its divisors is an integer number (5314411104678).

Almost surely, 2^{21212222101111} is an apocalyptic number.

21212222101111 is a deficient number, since it is larger than the sum of its proper divisors (45422317601).

21212222101111 is an equidigital number, since it uses as much as digits as its factorization.

21212222101111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45422317600.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21212222101111 its reverse (11110122221212), we get a palindrome (32322344322323).

The spelling of 21212222101111 in words is "twenty-one trillion, two hundred twelve billion, two hundred twenty-two million, one hundred one thousand, one hundred eleven".