21533444411 has 16 divisors (see below), whose sum is σ = 22149811200. Its totient is φ = 20922632640.

The previous prime is 21533444407. The next prime is 21533444419. The reversal of 21533444411 is 11444433512.

It is a cyclic number.

It is not a de Polignac number, because 21533444411 - 2² = 21533444407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21533444419) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8060606 + ... + 8063276.

It is an arithmetic number, because the mean of its divisors is an integer number (1384363200).

Almost surely, 2^21533444411 is an apocalyptic number.

21533444411 is a deficient number, since it is larger than the sum of its proper divisors (616366789).

21533444411 is a wasteful number, since it uses less digits than its factorization.

21533444411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3626.

The product of its digits is 23040, while the sum is 32.

Adding to 21533444411 its reverse (11444433512), we get a palindrome (32977877923).

The spelling of 21533444411 in words is "twenty-one billion, five hundred thirty-three million, four hundred forty-four thousand, four hundred eleven".