21212110022111 has 4 divisors (see below), whose sum is σ = 22328536865400. Its totient is φ = 20095683178824.

The previous prime is 21212110022009. The next prime is 21212110022177. The reversal of 21212110022111 is 11122001121212.

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 21212110022111 - 2³⁸ = 20937232115167 is a prime.

It is a super-3 number, since 3×21212110022111³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21212110022111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212110022711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 558213421616 + ... + 558213421653.

It is an arithmetic number, because the mean of its divisors is an integer number (5582134216350).

Almost surely, 2^{21212110022111} is an apocalyptic number.

21212110022111 is a deficient number, since it is larger than the sum of its proper divisors (1116426843289).

21212110022111 is a wasteful number, since it uses less digits than its factorization.

21212110022111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1116426843288.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21212110022111 its reverse (11122001121212), we get a palindrome (32334111143323).

The spelling of 21212110022111 in words is "twenty-one trillion, two hundred twelve billion, one hundred ten million, twenty-two thousand, one hundred eleven".