21533430205 has 32 divisors (see below), whose sum is σ = 31341634560. Its totient is φ = 13864796160.

The previous prime is 21533430199. The next prime is 21533430209. The reversal of 21533430205 is 50203433512.

It is not a de Polignac number, because 21533430205 - 2⁵ = 21533430173 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21533430209) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 214461 + ... + 298429.

It is an arithmetic number, because the mean of its divisors is an integer number (979426080).

Almost surely, 2^21533430205 is an apocalyptic number.

It is an amenable number.

21533430205 is a deficient number, since it is larger than the sum of its proper divisors (9808204355).

21533430205 is a wasteful number, since it uses less digits than its factorization.

21533430205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84429.

The product of its (nonzero) digits is 10800, while the sum is 28.

Adding to 21533430205 its reverse (50203433512), we get a palindrome (71736863717).

The spelling of 21533430205 in words is "twenty-one billion, five hundred thirty-three million, four hundred thirty thousand, two hundred five".