21213122311 has 4 divisors (see below), whose sum is σ = 21230611672. Its totient is φ = 21195632952.

The previous prime is 21213122303. The next prime is 21213122407. The reversal of 21213122311 is 11322131212.

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 21213122311 - 2³ = 21213122303 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 (21213122611) 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, 8742861 + ... + 8745286.

It is an arithmetic number, because the mean of its divisors is an integer number (5307652918).

Almost surely, 2^21213122311 is an apocalyptic number.

21213122311 is a deficient number, since it is larger than the sum of its proper divisors (17489361).

21213122311 is a wasteful number, since it uses less digits than its factorization.

21213122311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17489360.

The product of its digits is 144, while the sum is 19.

Adding to 21213122311 its reverse (11322131212), we get a palindrome (32535253523).

The spelling of 21213122311 in words is "twenty-one billion, two hundred thirteen million, one hundred twenty-two thousand, three hundred eleven".