21215324411 has 4 divisors (see below), whose sum is σ = 21531971112. Its totient is φ = 20898677712.

The previous prime is 21215324381. The next prime is 21215324443. The reversal of 21215324411 is 11442351212.

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 21215324411 - 2¹⁰ = 21215323387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21215320411) 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, 158323250 + ... + 158323383.

It is an arithmetic number, because the mean of its divisors is an integer number (5382992778).

Almost surely, 2^21215324411 is an apocalyptic number.

21215324411 is a deficient number, since it is larger than the sum of its proper divisors (316646701).

21215324411 is an equidigital number, since it uses as much as digits as its factorization.

21215324411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316646700.

The product of its digits is 1920, while the sum is 26.

Adding to 21215324411 its reverse (11442351212), we get a palindrome (32657675623).

The spelling of 21215324411 in words is "twenty-one billion, two hundred fifteen million, three hundred twenty-four thousand, four hundred eleven".