21032303021 has 4 divisors (see below), whose sum is σ = 21065013312. Its totient is φ = 20999592732.

The previous prime is 21032303009. The next prime is 21032303029. The reversal of 21032303021 is 12030323012.

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 not a de Polignac number, because 21032303021 - 2¹⁴ = 21032286637 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 (21032303029) 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, 16354181 + ... + 16355466.

It is an arithmetic number, because the mean of its divisors is an integer number (5266253328).

Almost surely, 2^21032303021 is an apocalyptic number.

It is an amenable number.

21032303021 is a deficient number, since it is larger than the sum of its proper divisors (32710291).

21032303021 is an equidigital number, since it uses as much as digits as its factorization.

21032303021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32710290.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21032303021 its reverse (12030323012), we get a palindrome (33062626033).

The spelling of 21032303021 in words is "twenty-one billion, thirty-two million, three hundred three thousand, twenty-one".