21303332533 has 4 divisors (see below), whose sum is σ = 24346665760. Its totient is φ = 18259999308.

The previous prime is 21303332521. The next prime is 21303332569. The reversal of 21303332533 is 33523330312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21303332533 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 (21303332503) 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, 1521666603 + ... + 1521666616.

It is an arithmetic number, because the mean of its divisors is an integer number (6086666440).

Almost surely, 2^21303332533 is an apocalyptic number.

It is an amenable number.

21303332533 is a deficient number, since it is larger than the sum of its proper divisors (3043333227).

21303332533 is an equidigital number, since it uses as much as digits as its factorization.

21303332533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3043333226.

The product of its (nonzero) digits is 14580, while the sum is 28.

Adding to 21303332533 its reverse (33523330312), we get a palindrome (54826662845).

The spelling of 21303332533 in words is "twenty-one billion, three hundred three million, three hundred thirty-two thousand, five hundred thirty-three".