21212112311 has 4 divisors (see below), whose sum is σ = 22843813272. Its totient is φ = 19580411352.

The previous prime is 21212112209. The next prime is 21212112401. The reversal of 21212112311 is 11321121212.

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 21212112311 - 2³⁰ = 20138370487 is a prime.

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 21212112311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212115311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 815850461 + ... + 815850486.

It is an arithmetic number, because the mean of its divisors is an integer number (5710953318).

Almost surely, 2^21212112311 is an apocalyptic number.

21212112311 is a deficient number, since it is larger than the sum of its proper divisors (1631700961).

21212112311 is a wasteful number, since it uses less digits than its factorization.

21212112311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631700960.

The product of its digits is 48, while the sum is 17.

Adding to 21212112311 its reverse (11321121212), we get a palindrome (32533233523).

The spelling of 21212112311 in words is "twenty-one billion, two hundred twelve million, one hundred twelve thousand, three hundred eleven".