21212021110111 has 4 divisors (see below), whose sum is σ = 22843715041672. Its totient is φ = 19580327178552.

The previous prime is 21212021110109. The next prime is 21212021110121. The reversal of 21212021110111 is 11101112021212.

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 21212021110111 - 2¹ = 21212021110109 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 (21212021110121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 815846965761 + ... + 815846965786.

It is an arithmetic number, because the mean of its divisors is an integer number (5710928760418).

Almost surely, 2^{21212021110111} is an apocalyptic number.

21212021110111 is a deficient number, since it is larger than the sum of its proper divisors (1631693931561).

21212021110111 is a wasteful number, since it uses less digits than its factorization.

21212021110111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631693931560.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21212021110111 its reverse (11101112021212), we get a palindrome (32313133131323).

The spelling of 21212021110111 in words is "twenty-one trillion, two hundred twelve billion, twenty-one million, one hundred ten thousand, one hundred eleven".