21305203536 has 40 divisors (see below), whose sum is σ = 55091850880. Its totient is φ = 7094843136.

The previous prime is 21305203459. The next prime is 21305203553. The reversal of 21305203536 is 63530250312.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 165256 + ... + 264423.

It is an arithmetic number, because the mean of its divisors is an integer number (1377296272).

Almost surely, 2^21305203536 is an apocalyptic number.

It is an amenable number.

21305203536 is an abundant number, since it is smaller than the sum of its proper divisors (33786647344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21305203536 is a wasteful number, since it uses less digits than its factorization.

21305203536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430723 (or 430717 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 30.

Adding to 21305203536 its reverse (63530250312), we get a palindrome (84835453848).

The spelling of 21305203536 in words is "twenty-one billion, three hundred five million, two hundred three thousand, five hundred thirty-six".